diff --git a/cadet/cadet_dll_utils.py b/cadet/cadet_dll_utils.py
index 383f44d..cc9ada5 100644
--- a/cadet/cadet_dll_utils.py
+++ b/cadet/cadet_dll_utils.py
@@ -14,6 +14,7 @@ def null(*args: Any) -> None:
 
 # %% Single entries
 
+
 def param_provider_get_double(
         reader: Any,
         name: ctypes.c_char_p,
@@ -41,15 +42,22 @@ def param_provider_get_double(
 
     if n in c:
         o = c[n]
+
+        # Safely handle scalars and lists
         try:
-            float_val = float(o)
-        except TypeError:
-            float_val = float(o[0])
+            if isinstance(o, (list, np.ndarray)):
+                float_val = float(o[0])  # Use the first element for arrays/lists
+            else:
+                float_val = float(o)
+        except (TypeError, ValueError, IndexError) as e:
+            log_print(f"Error converting {n} to double: {e}")
+            return -1
 
         val[0] = ctypes.c_double(float_val)
-        log_print(f"GET scalar [double] {n}: {float(val[0])}")
+        log_print(f"GET scalar [double] {n}: {float_val}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -80,15 +88,22 @@ def param_provider_get_int(
 
     if n in c:
         o = c[n]
+
+        # Safely handle scalars and lists
         try:
-            int_val = int(o)
-        except TypeError:
-            int_val = int(o[0])
+            if isinstance(o, (list, np.ndarray)):
+                int_val = np.int32(o[0])  # Use the first element for arrays/lists
+            else:
+                int_val = np.int32(o)
+        except (TypeError, ValueError, IndexError) as e:
+            log_print(f"Error converting {n} to int: {e}")
+            return -1
 
         val[0] = ctypes.c_int(int_val)
-        log_print(f"GET scalar [int] {n}: {int(val[0])}")
+        log_print(f"GET scalar [int] {n}: {int_val}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -119,15 +134,22 @@ def param_provider_get_bool(
 
     if n in c:
         o = c[n]
+
+        # Safely handle scalars and lists
         try:
-            int_val = int(o)
-        except TypeError:
-            int_val = int(o[0])
+            if isinstance(o, (list, np.ndarray)):
+                bool_val = bool(o[0])  # Use the first element for arrays/lists
+            else:
+                bool_val = bool(o)
+        except (TypeError, ValueError, IndexError) as e:
+            log_print(f"Error converting {n} to bool: {e}")
+            return -1
 
-        val[0] = ctypes.c_uint8(int_val)
+        val[0] = ctypes.c_uint8(bool_val)
         log_print(f"GET scalar [bool] {n}: {bool(val[0])}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -159,22 +181,32 @@ def param_provider_get_string(
     if n in c:
         o = c[n]
 
-        if hasattr(o, 'encode'):
-            bytes_val = o.encode('utf-8')
-        elif hasattr(o, 'decode'):
-            bytes_val = o
-        elif hasattr(o[0], 'encode'):
-            bytes_val = o[0].encode('utf-8')
-        elif hasattr(o[0], 'decode'):
-            bytes_val = o[0]
+        # Safely handle string conversions
+        try:
+            if isinstance(o, str):
+                bytes_val = o.encode('utf-8')
+            elif isinstance(o, bytes):
+                bytes_val = o
+            elif isinstance(o, (list, np.ndarray)) and isinstance(o[0], str):
+                bytes_val = o[0].encode('utf-8')  # Use the first element
+            elif isinstance(o, (list, np.ndarray)) and isinstance(o[0], bytes):
+                bytes_val = o[0]
+            else:
+                log_print(f"Error: Unsupported type for parameter {n}.")
+                return -1
+        except (TypeError, ValueError, IndexError) as e:
+            log_print(f"Error converting {n} to string: {e}")
+            return -1
 
+        # Store in reader's buffer
         reader.buffer = bytes_val
         val[0] = ctypes.cast(reader.buffer, ctypes.c_char_p)
+        log_print(f"GET scalar [string] {n}: {reader.buffer.decode('utf-8')}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
-
 # %% Arrays
 
 def param_provider_get_double_array(
@@ -207,16 +239,25 @@ def param_provider_get_double_array(
 
     if n in c:
         o = c[n]
-        if isinstance(o, list):
-            o = np.ascontiguousarray(o)
+
+        # Ensure object is a properly aligned numpy array
+        if isinstance(o, list):  # Convert lists to numpy arrays
+            o = np.array(o, dtype=np.double)
+            c[n] = o  # Update the reader's storage
+
+        # Validate the array
         if not isinstance(o, np.ndarray) or o.dtype != np.double or not o.flags.c_contiguous:
+            log_print(f"Error: Parameter {n} is not a contiguous double array.")
             return -1
 
+        # Provide array data to the caller
         n_elem[0] = ctypes.c_int(o.size)
-        val[0] = o.ctypes.data_as(ctypes.POINTER(ctypes.c_double))
+        val[0] = np.ctypeslib.as_ctypes(o)
+
         log_print(f"GET array [double] {n}: {o}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -250,9 +291,11 @@ def param_provider_get_int_array(
 
     if n in c:
         o = c[n]
-        if isinstance(o, list):
-            o = np.ascontiguousarray(o)
-        if not isinstance(o, np.ndarray) or o.dtype != int or not o.flags.c_contiguous:
+        if isinstance(o, list):  # Convert lists to numpy arrays
+            o = np.array(o, dtype=np.int32)
+            c[n] = o  # Update the reader's storage
+        if not isinstance(o, np.ndarray) or o.dtype != np.int32 or not o.flags.c_contiguous:
+            log_print(f"Error: Parameter {n} is not a contiguous int array.")
             return -1
 
         n_elem[0] = ctypes.c_int(o.size)
@@ -295,15 +338,29 @@ def param_provider_get_double_array_item(
     if n in c:
         o = c[n]
 
+        # Ensure the object is a numpy array
+        if isinstance(o, list):
+            o = np.array(o, dtype=np.double, copy=True)
+            c[n] = o  # Update the reader's storage for consistency
+        elif isinstance(o, np.ndarray):
+            o = np.ascontiguousarray(o, dtype=np.double)  # Ensure it is contiguous and has correct dtype
+
+        if not (isinstance(o, np.ndarray) and o.dtype == np.double and o.flags.c_contiguous):
+            log_print(f"Error: Parameter {n} is not a valid double array.")
+            return -1
+
+        # Safely retrieve the indexed item
         try:
-            float_val = float(o)
-        except TypeError:
             float_val = float(o[index])
+        except (IndexError, ValueError, TypeError) as e:
+            log_print(f"Error accessing index {index} for parameter {n}: {e}")
+            return -1
 
         val[0] = ctypes.c_double(float_val)
-        log_print(f"GET array [double] ({index}) {n}: {val[0]}")
+        log_print(f"GET array [double] ({index}) {n}: {float_val}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -315,22 +372,6 @@ def param_provider_get_int_array_item(
         ) -> int:
     """
     Retrieve an item from an integer array in the reader based on the provided name and index.
-
-    Parameters
-    ----------
-    reader : Any
-        The reader object containing the current data scope.
-    name : ctypes.c_char_p
-        The name of the parameter to retrieve.
-    index : int
-        The index of the array item to retrieve.
-    val : ctypes.POINTER(ctypes.c_int)
-        A pointer to store the retrieved integer value.
-
-    Returns
-    -------
-    int
-        0 if the value was found and retrieved successfully, -1 otherwise.
     """
     n = name.decode('utf-8')
     c = reader.current()
@@ -338,15 +379,29 @@ def param_provider_get_int_array_item(
     if n in c:
         o = c[n]
 
+        # Ensure the object is a numpy array
+        if isinstance(o, list):
+            o = np.array(o, dtype=np.int32, copy=True)
+            c[n] = o  # Update the reader's storage for consistency
+        elif isinstance(o, np.ndarray):
+            o = np.ascontiguousarray(o, dtype=np.int32)
+
+        if not (isinstance(o, np.ndarray) and o.dtype == np.int32 and o.flags.c_contiguous):
+            log_print(f"Error: Parameter {n} is not a valid int32 array.")
+            return -1
+
+        # Retrieve the indexed item
         try:
-            int_val = int(o)
-        except TypeError:
             int_val = int(o[index])
+        except (IndexError, ValueError, TypeError) as e:
+            log_print(f"Error accessing index {index} for parameter {n}: {e}")
+            return -1
 
         val[0] = ctypes.c_int(int_val)
-        log_print(f"GET array [int] ({index}) {n}: {val[0]}")
+        log_print(f"GET array [int] ({index}) {n}: {int_val}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -358,22 +413,6 @@ def param_provider_get_bool_array_item(
         ) -> int:
     """
     Retrieve an item from a boolean array in the reader based on the provided name and index.
-
-    Parameters
-    ----------
-    reader : Any
-        The reader object containing the current data scope.
-    name : ctypes.c_char_p
-        The name of the parameter to retrieve.
-    index : int
-        The index of the array item to retrieve.
-    val : ctypes.POINTER(ctypes.c_uint8)
-        A pointer to store the retrieved boolean value.
-
-    Returns
-    -------
-    int
-        0 if the value was found and retrieved successfully, -1 otherwise.
     """
     n = name.decode('utf-8')
     c = reader.current()
@@ -381,15 +420,29 @@ def param_provider_get_bool_array_item(
     if n in c:
         o = c[n]
 
+        # Ensure the object is a numpy array
+        if isinstance(o, list):
+            o = np.array(o, dtype=np.bool_, copy=True)
+            c[n] = o  # Update the reader's storage for consistency
+        elif isinstance(o, np.ndarray):
+            o = np.ascontiguousarray(o, dtype=np.bool_)
+
+        if not (isinstance(o, np.ndarray) and o.dtype == np.bool_ and o.flags.c_contiguous):
+            log_print(f"Error: Parameter {n} is not a valid bool array.")
+            return -1
+
+        # Retrieve the indexed item
         try:
-            int_val = int(o)
-        except TypeError:
-            int_val = int(o[index])
+            bool_val = bool(o[index])
+        except (IndexError, ValueError, TypeError) as e:
+            log_print(f"Error accessing index {index} for parameter {n}: {e}")
+            return -1
 
-        val[0] = ctypes.c_uint8(int_val)
+        val[0] = ctypes.c_uint8(bool_val)
         log_print(f"GET array [bool] ({index}) {n}: {bool(val[0])}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1
 
 
@@ -401,45 +454,38 @@ def param_provider_get_string_array_item(
         ) -> int:
     """
     Retrieve an item from a string array in the reader based on the provided name and index.
+    """
+    n = name.decode('utf-8')
+    c = reader.current()
 
-    Parameters
-    ----------
-    reader : Any
-        The reader object containing the current data scope.
-    name : ctypes.c_char_p
-        The name of the parameter to retrieve.
-    index : int
-        The index of the array item to retrieve.
-    val : ctypes.POINTER(ctypes.c_char_p)
-        A pointer to store the retrieved string value.
+    if n in c:
+        o = c[n]
 
-    Returns
-    -------
-    int
-        0 if the value was found and retrieved successfully, -1 otherwise.
-    """
-    name_str = name.decode('utf-8')
-    current_reader = reader.current()
-
-    if name_str in current_reader:
-        str_value = current_reader[name_str]
-        if isinstance(str_value, bytes):
-            bytes_val = str_value
-        elif isinstance(str_value, str):
-            bytes_val = str_value.encode('utf-8')
-        elif isinstance(str_value, np.ndarray):
-            bytes_val = str_value[index]
-        else:
-            raise TypeError(
-                "Unexpected type for str_value. "
-                "Must be of type bytes, str, or np.ndarray."
-            )
+        # Ensure the object is a numpy array
+        if isinstance(o, list):
+            o = np.array(o, dtype=np.str_, copy=True)
+            c[n] = o  # Update the reader's storage for consistency
+        elif isinstance(o, np.ndarray):
+            o = np.ascontiguousarray(o, dtype=np.str_)
 
-        reader.buffer = bytes_val
+        if not (isinstance(o, np.ndarray) and o.dtype.kind == 'U' and o.flags.c_contiguous):
+            log_print(f"Error: Parameter {n} is not a valid string array.")
+            return -1
+
+        # Retrieve the indexed item
+        try:
+            string_val = o[index]
+        except (IndexError, ValueError, TypeError) as e:
+            log_print(f"Error accessing index {index} for parameter {n}: {e}")
+            return -1
+
+        # Encode to UTF-8 and store in reader.buffer
+        reader.buffer = string_val.encode('utf-8')
         val[0] = ctypes.cast(reader.buffer, ctypes.c_char_p)
-        log_print(f"GET array [string] ({index}) {name_str}: {reader.buffer.decode('utf-8')}")
+        log_print(f"GET array [string] ({index}) {n}: {reader.buffer.decode('utf-8')}")
         return 0
 
+    log_print(f"Parameter {n} not found.")
     return -1