diff --git a/build.gradle b/build.gradle
index 761acf6..042b805 100644
--- a/build.gradle
+++ b/build.gradle
@@ -44,6 +44,7 @@ jar {
 
     into 'res', {
         from 'res'
+        exclude 'extlibs/'
     }
 
     into 'licenses', {
diff --git a/src/main/java/se306/a1/scheduler/util/parse/CLIParser.java b/src/main/java/se306/a1/scheduler/util/parse/CLIParser.java
index 8500a6a..a08a927 100644
--- a/src/main/java/se306/a1/scheduler/util/parse/CLIParser.java
+++ b/src/main/java/se306/a1/scheduler/util/parse/CLIParser.java
@@ -91,6 +91,9 @@ public InputConfig parseCLI(String[] args) throws ParseException, CLIException {
 
             if (isInteger(stringCores)) {
                 config.cores = Integer.parseInt(stringCores);
+                if (config.cores < 1) {
+                    throw new CLIException("Number of cores specified cannot be less than 1");
+                }
                 logger.info("Has specified parallel option: number of cores = " + config.cores);
             } else {
                 logger.error("Number of cores is not an integer");
diff --git a/src/main/java/se306/a1/scheduler/util/parse/GraphParser.java b/src/main/java/se306/a1/scheduler/util/parse/GraphParser.java
index c1ab842..a27a323 100644
--- a/src/main/java/se306/a1/scheduler/util/parse/GraphParser.java
+++ b/src/main/java/se306/a1/scheduler/util/parse/GraphParser.java
@@ -43,6 +43,10 @@ public static Graph parse(String inputPath) throws IOException, GraphException {
         Map<String, Node> nodes = new HashMap<>();
         List<Edge> edges = new ArrayList<>();
 
+        if (parsedNodes.values().isEmpty()) {
+            throw new GraphException("No nodes contained in the graph");
+        }
+
         for (GraphNode node : parsedNodes.values()) {
             String label = node.getId();