diff --git a/src/main/java/com/crowdin/client/Crowdin.java b/src/main/java/com/crowdin/client/Crowdin.java
index f213e8b..2eaa4c6 100644
--- a/src/main/java/com/crowdin/client/Crowdin.java
+++ b/src/main/java/com/crowdin/client/Crowdin.java
@@ -407,17 +407,16 @@ private <T> T executeRequest(Supplier<T> exec) {
         try {
             return exec.get();
         } catch (HttpException e) {
-            HttpException ex = (HttpException) e;
-            String code = (ex.getError() != null && ex.getError().getCode() != null) ? ex.getError().getCode() : "<empty_code>";
-            String message = (ex.getError() != null && ex.getError().getMessage() != null) ? ex.getError().getMessage() : "<empty_message>";
+            String code = (e.getError() != null && e.getError().getCode() != null) ? e.getError().getCode() : "empty_code";
+            String message = (e.getError() != null && e.getError().getMessage() != null) ? e.getError().getMessage() : "empty_message";
             String errorMessage = ("401".equals(code))
                     ? MESSAGES_BUNDLE.getString("errors.authorize")
-                    : String.format("Error from server: <Code: %s, Message: %s>", code, message);
+                    : String.format("Error from server: Code: %s, Message: %s", code, message);
             throw new RuntimeException(errorMessage, e);
         } catch (HttpBadRequestException e) {
             String errorMessage;
             if (e.getErrors() == null) {
-                errorMessage = "Wrong parameters: <Key: <empty_key>, Code: <empty_code>, Message: <empty_message>";
+                errorMessage = "Wrong parameters: Key: empty_key, Code: empty_code, Message: empty_message";
             } else {
                 errorMessage = "Wrong parameters: \n" + e.getErrors()
                         .stream()
@@ -426,10 +425,10 @@ private <T> T executeRequest(Supplier<T> exec) {
                                 .stream()
                                 .filter(Objects::nonNull)
                                 .map(error ->
-                                        String.format("<Key: %s, Code: %s, Message: %s>",
-                                                (holder.getKey() != null) ? holder.getKey() : "<empty_key>",
-                                                (error.getCode() != null) ? error.getCode() : "<empty_code>",
-                                                (error.getMessage() != null) ? error.getMessage() : "<empty_message>")))
+                                        String.format("Key: %s, Code: %s, Message: %s",
+                                                (holder.getKey() != null) ? holder.getKey() : "empty_key",
+                                                (error.getCode() != null) ? error.getCode() : "empty_code",
+                                                (error.getMessage() != null) ? error.getMessage() : "empty_message")))
                         .collect(Collectors.joining("\n"));
             }
             throw new RuntimeException(errorMessage, e);
diff --git a/src/main/java/com/crowdin/client/config/CrowdinFileProvider.java b/src/main/java/com/crowdin/client/config/CrowdinFileProvider.java
index 2552a04..e78a239 100644
--- a/src/main/java/com/crowdin/client/config/CrowdinFileProvider.java
+++ b/src/main/java/com/crowdin/client/config/CrowdinFileProvider.java
@@ -23,6 +23,8 @@ public static Map<String, Object> load(Project project) {
         }
         try (InputStream in = crowdinPropertyFile.getInputStream()) {
             return YAML.load(in);
+        } catch (ClassCastException e) {
+            throw new RuntimeException(MESSAGES_BUNDLE.getString("errors.config.has_errors") + "The Yaml file is not in the correct format");
         } catch (IOException e) {
             throw new RuntimeException(MESSAGES_BUNDLE.getString("errors.config.has_errors") + e.getMessage());
         }
diff --git a/src/main/java/com/crowdin/client/config/CrowdinPropertiesLoader.java b/src/main/java/com/crowdin/client/config/CrowdinPropertiesLoader.java
index e5b255f..5c007e5 100644
--- a/src/main/java/com/crowdin/client/config/CrowdinPropertiesLoader.java
+++ b/src/main/java/com/crowdin/client/config/CrowdinPropertiesLoader.java
@@ -11,6 +11,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import static com.crowdin.Constants.CONFIG_FILE;
 import static com.crowdin.Constants.MESSAGES_BUNDLE;
@@ -59,7 +60,7 @@ protected static CrowdinConfig load(Map<String, Object> properties, CrowdingSett
             try {
 
                 Object propProjectId = properties.get(PROJECT_ID);
-                String propProjectIdEnv = (String) properties.get(PROJECT_ID_ENV);
+                String propProjectIdEnv = getStringProperty(properties, PROJECT_ID_ENV);
 
                 if (propProjectId != null) {
                     try {
@@ -88,8 +89,8 @@ protected static CrowdinConfig load(Map<String, Object> properties, CrowdingSett
                     errors.add(String.format(MESSAGES_BUNDLE.getString("errors.config.missing_property"), PROJECT_ID));
                 }
 
-                String propApiToken = (String) properties.get(API_TOKEN);
-                String propApiTokenEnv = (String) properties.get(API_TOKEN_ENV);
+                String propApiToken = getStringProperty(properties, API_TOKEN);
+                String propApiTokenEnv = getStringProperty(properties, API_TOKEN_ENV);
                 if (!StringUtils.isEmpty(propApiToken)) {
                     crowdinProperties.setApiToken(propApiToken);
                 } else if (!StringUtils.isEmpty(propApiTokenEnv)) {
@@ -105,8 +106,8 @@ protected static CrowdinConfig load(Map<String, Object> properties, CrowdingSett
                     errors.add(String.format(MESSAGES_BUNDLE.getString("errors.config.missing_property"), API_TOKEN));
                 }
 
-                String propBaseUrl = (String) properties.get(BASE_URL);
-                String propBaseUrlEnv = (String) properties.get(BASE_URL_ENV);
+                String propBaseUrl = getStringProperty(properties, BASE_URL);
+                String propBaseUrlEnv = getStringProperty(properties, BASE_URL_ENV);
                 if (!StringUtils.isEmpty(propBaseUrl)) {
                     if (isBaseUrlValid(propBaseUrl)) {
                         crowdinProperties.setBaseUrl(propBaseUrl);
@@ -144,22 +145,22 @@ protected static CrowdinConfig load(Map<String, Object> properties, CrowdingSett
                 crowdinProperties.setAutocompletionEnabled(settings.enableCompletion);
 
                 crowdinProperties.setUseGitBranch(settings.useGitBranch);
-                Boolean preserveHierarchy = (Boolean) properties.get(PROPERTY_PRESERVE_HIERARCHY);
+                Boolean preserveHierarchy = getBooleanProperty(properties, PROPERTY_PRESERVE_HIERARCHY);
                 crowdinProperties.setPreserveHierarchy(preserveHierarchy);
-                Boolean debug = (Boolean) properties.get(PROPERTY_DEBUG);
+                Boolean debug = getBooleanProperty(properties, PROPERTY_DEBUG);
                 crowdinProperties.setDebug(debug);
-                Boolean importEqSuggestions = (Boolean) properties.get(PROPERTY_IMPORT_EQ_SUGGESTIONS);
+                Boolean importEqSuggestions = getBooleanProperty(properties, PROPERTY_IMPORT_EQ_SUGGESTIONS);
                 crowdinProperties.setImportEqSuggestions(importEqSuggestions);
-                Boolean autoApproveImported = (Boolean) properties.get(PROPERTY_AUTO_APPROVE_IMPORTED);
+                Boolean autoApproveImported = getBooleanProperty(properties, PROPERTY_AUTO_APPROVE_IMPORTED);
                 crowdinProperties.setAutoApproveImported(autoApproveImported);
-                Boolean translateHidden = (Boolean) properties.get(PROPERTY_TRANSLATE_HIDDEN);
+                Boolean translateHidden = getBooleanProperty(properties, PROPERTY_TRANSLATE_HIDDEN);
                 crowdinProperties.setTranslateHidden(translateHidden);
-                String branch = (String) properties.get(PROPERTY_BRANCH);
+                String branch = getStringProperty(properties, PROPERTY_BRANCH);
                 crowdinProperties.setBranch(branch);
 
             } catch (Exception e) {
                 e.printStackTrace();
-                throw new RuntimeException(MESSAGES_BUNDLE.getString("errors.config.has_errors") + e.getMessage());
+                throw new RuntimeException(MESSAGES_BUNDLE.getString("errors.config.has_errors") + " " + e.getMessage());
             }
         }
 
@@ -173,16 +174,16 @@ protected static CrowdinConfig load(Map<String, Object> properties, CrowdingSett
     private static List<FileBean> getSourcesWithTranslations(Map<String, Object> properties, List<String> errors) {
         List<FileBean> fileBeans = new ArrayList<>();
 
-        List<Map<String, Object>> files = (List<Map<String, Object>>) properties.get(PROPERTY_FILES);
+        List<Map<String, Object>> files = getListOfObjectsProperty(properties, PROPERTY_FILES);
 
         if (files != null) {
             files.forEach(file -> {
-                String source = (String) file.get(PROPERTY_FILES_SOURCE);
-                String translation = (String) file.get(PROPERTY_FILES_TRANSLATION);
-                Boolean updateStrings = (Boolean) file.get(PROPERTY_FILES_UPDATE_STRINGS);
-                Boolean cleanupMode = (Boolean) file.get(PROPERTY_FILES_CLEANUP_MODE);
-                List<String> labels = (List<String>) file.get(PROPERTY_LABELS);
-                List<String> excludedTargetLanguages = (List<String>) file.get(PROPERTY_EXCLUDED_TARGET_LANGUAGES);
+                String source = getStringProperty(file, PROPERTY_FILES_SOURCE);
+                String translation = getStringProperty(file, PROPERTY_FILES_TRANSLATION);
+                Boolean updateStrings = getBooleanProperty(file, PROPERTY_FILES_UPDATE_STRINGS);
+                Boolean cleanupMode = getBooleanProperty(file, PROPERTY_FILES_CLEANUP_MODE);
+                List<String> labels = getListStringsProperty(file, PROPERTY_LABELS);
+                List<String> excludedTargetLanguages = getListStringsProperty(file, PROPERTY_EXCLUDED_TARGET_LANGUAGES);
 
                 if (!StringUtils.isEmpty(source) && !StringUtils.isEmpty(translation)) {
                     FileBean fb = new FileBean();
@@ -193,9 +194,9 @@ private static List<FileBean> getSourcesWithTranslations(Map<String, Object> pro
                     fb.setUpdateStrings(updateStrings);
                     fb.setCleanupMode(cleanupMode);
                     fileBeans.add(fb);
-                } else if (StringUtils.isEmpty(translation)) {
-                    errors.add(String.format(MESSAGES_BUNDLE.getString("errors.config.missing_property"), PROPERTY_FILES_SOURCE));
                 } else if (StringUtils.isEmpty(source)) {
+                    errors.add(String.format(MESSAGES_BUNDLE.getString("errors.config.missing_property"), PROPERTY_FILES_SOURCE));
+                } else if (StringUtils.isEmpty(translation)) {
                     errors.add(String.format(MESSAGES_BUNDLE.getString("errors.config.missing_property"), PROPERTY_FILES_TRANSLATION));
                 }
             });
@@ -204,6 +205,75 @@ private static List<FileBean> getSourcesWithTranslations(Map<String, Object> pro
         return fileBeans;
     }
 
+    private static String getStringProperty(Map<String, Object> map, String property) {
+        return getProperty(map, property, String.class);
+    }
+
+    private static List<String> getListStringsProperty(Map<String, Object> map, String property) {
+        List list = getProperty(map, property, List.class);
+        if (list == null) {
+            return null;
+        }
+        List<String> res = new ArrayList<>();
+        for (int i = 0; i < list.size(); i++) {
+            Object el = list.get(i);
+            try {
+                res.add(String.class.cast(el));
+            } catch (ClassCastException e) {
+                throw new RuntimeException(String.format(MESSAGES_BUNDLE.getString("errors.config.invalid_format"), String.format("%s[%s]", property, i)));
+            }
+        }
+        return res;
+    }
+
+    private static List<Map<String, Object>> getListOfObjectsProperty(Map<String, Object> map, String property) {
+        List list = getProperty(map, property, List.class);
+        if (list == null) {
+            return null;
+        }
+        List<Map<String, Object>> res = new ArrayList<>();
+        for (int i = 0; i < list.size(); i++) {
+            Object el = list.get(i);
+            try {
+                Map<Object, Object> object = Map.class.cast(el);
+
+                int finalI = i;
+                Map<String, Object> castedObject = object
+                        .entrySet()
+                        .stream()
+                        .peek(entry -> {
+                            if (entry.getKey() == null || entry.getValue() == null) {
+                                throw new RuntimeException(String.format(MESSAGES_BUNDLE.getString("errors.config.invalid_format"), String.format("%s[%s]", property, finalI)));
+                            }
+                        })
+                        .collect(Collectors.toMap(
+                                field -> String.class.cast(field.getKey()),
+                                Map.Entry::getValue
+                        ));
+                res.add(castedObject);
+            } catch (ClassCastException e) {
+                throw new RuntimeException(String.format(MESSAGES_BUNDLE.getString("errors.config.invalid_format"), String.format("%s[%s]", property, i)));
+            }
+        }
+        return res;
+    }
+
+    private static Boolean getBooleanProperty(Map<String, Object> map, String property) {
+        return getProperty(map, property, Boolean.class);
+    }
+
+    private static <T> T getProperty(Map<String, Object> map, String property, Class<T> clazz) {
+        try {
+            Object value = map.get(property);
+            if (value != null) {
+                return clazz.cast(value);
+            }
+            return null;
+        } catch (ClassCastException e) {
+            throw new RuntimeException(String.format(MESSAGES_BUNDLE.getString("errors.config.invalid_format"), property));
+        }
+    }
+
     protected static boolean isBaseUrlValid(String baseUrl) {
         return BASE_URL_PATTERN.matcher(baseUrl).matches();
     }
diff --git a/src/main/resources/messages/messages.properties b/src/main/resources/messages/messages.properties
index c68072e..b409a58 100644
--- a/src/main/resources/messages/messages.properties
+++ b/src/main/resources/messages/messages.properties
@@ -11,7 +11,7 @@ labels.loading_text.download_source_file_from_context=Downloading Source File '%
 errors.config.project_id_format=Project Id '%s' should be a number
 errors.config.sysenv_not_exist.single=Environment variables do not contain <b>'%s'</b> key
 errors.config.sysenv_not_exist.plural=Environment variables do not contain %s keys
-errors.settings.api_token_missing=API Token is not defined for this workspace
+errors.config.invalid_format=Property '%s' has wrong format
 errors.config.has_errors=Errors in the configuration file:
 errors.config.missing_config_file=File <b>'%s'</b> with Crowdin plugin configuration doesn't exist in the project root directory
 errors.config.missing_property=Required property <b>'%s'</b> is missing in the configuration file