diff --git a/include/sdutils/sdutils.h b/include/sdutils/sdutils.h
index f24f6c9..db8cf03 100644
--- a/include/sdutils/sdutils.h
+++ b/include/sdutils/sdutils.h
@@ -16,6 +16,7 @@ typedef enum SDUtilsStatus {
     SDUTILS_RESULT_FAILED                = -0x10,
     SDUTILS_RESULT_LIB_UNINITIALIZED     = -0x20,
     SDUTILS_RESULT_UNSUPPORTED_VERSION   = -0x99,
+    SDUTILS_RESULT_UNSUPPORTED_COMMAND   = -0x100,
     SDUTILS_RESULT_UNKNOWN_ERROR         = -0x1000,
 } SDUtilsStatus;
 
@@ -33,8 +34,8 @@ typedef void (*SDCleanUpHandlesHandlerFn)();
 
 /**
  * Initializes the SDUtils library. This must be call before any other function can be called
- * @return SDUTILS_RESULT_SUCCESS on success, the functions of this lib can be used
- *         SDUTILS_RESULT_MODULE_NOT_FOUND when the SDHotSwapModule is not loaded
+ * @return SDUTILS_RESULT_SUCCESS on success, the functions of this lib can be used <br>
+ *         SDUTILS_RESULT_MODULE_NOT_FOUND when the SDHotSwapModule is not loaded <br>
  *         SDUTILS_RESULT_MODULE_MISSING_EXPORT when the SDHotSwapModule does not export the expected functions.
  */
 SDUtilsStatus SDUtils_InitLibrary();
@@ -59,19 +60,20 @@ SDUtilsStatus SDUtils_DeInitLibrary();
 SDUtilsStatus SDUtils_GetVersion(SDUtilsVersion *outVersion);
 
 /**
- * Registers a callback which will be called whenever a sd card will be inserted or ejected.
- * This is only true for future events, if the sd card is already inserted before registering
- * a callback, the callback is only called on the next ejecting but not for the initial
- * insertion that happened in the past.
- *
- * Any previously registered callbacks will be removed when the currently running application
- * is closing.
+ * Registers a callback which will be called whenever a sd card will be inserted or ejected. <br>
+ * This is only true for future events, if the sd card is already inserted before registering <br>
+ * a callback, the callback is only called on the next ejecting but not for the initial <br>
+ * insertion that happened in the past. <br>
+ * <br>
+ * Any previously registered callbacks will be removed when the currently running application <br>
+ * is closing. <br>
  *
  * @param fn callback that will be called
- * @return SDUTILS_RESULT_SUCCESS on success
- *         SDUTILS_RESULT_MAX_CALLBACKS when registering the callback has failed because the
- *                                      maximum amount of callback has been reached
- *         SDUTILS_RESULT_LIB_UNINITIALIZED if the lib was not initialized properly
+ * @return SDUTILS_RESULT_SUCCESS on success <br>
+ *         SDUTILS_RESULT_MAX_CALLBACKS         when registering the callback has failed because the <br>
+ *                                              maximum amount of callback has been reached <br>
+ *         SDUTILS_RESULT_LIB_UNINITIALIZED     if the lib was not initialized properly <br>
+ *         SDUTILS_RESULT_UNSUPPORTED_COMMAND   Command not supported by the currently running module
  */
 SDUtilsStatus SDUtils_AddAttachHandler(SDAttachHandlerFn fn);
 
@@ -79,27 +81,29 @@ SDUtilsStatus SDUtils_AddAttachHandler(SDAttachHandlerFn fn);
  * Removed a previously registered callback
  *
  * @param fn
- * @return SDUTILS_RESULT_SUCCESS on success
- *         SDUTILS_RESULT_NOT_FOUND when the given callback was not registered.
- *         SDUTILS_RESULT_LIB_UNINITIALIZED if the lib was not initialized properly
+ * @return SDUTILS_RESULT_SUCCESS               on success <br>
+ *         SDUTILS_RESULT_NOT_FOUND             when the given callback was not registered. <br>
+ *         SDUTILS_RESULT_LIB_UNINITIALIZED     if the lib was not initialized properly <br>
+ *         SDUTILS_RESULT_UNSUPPORTED_COMMAND   Command not supported by the currently running module
  */
 SDUtilsStatus SDUtils_RemoveAttachHandler(SDAttachHandlerFn fn);
 
 /**
- * Registers a callback which will be called whenever a sd card will be ejected and before
- * the SDUtils_AddAttachHandler. This callback is supposed to be used to clean up any open
- * file handles before the sd card gets unmounted.
- * This is only true for future events, if the sd card is already ejected before registering
- * a callback, the callback is only called on the next ejecting.
- *
- * Any previously registered callbacks will be removed when the currently running application
- * is closing.
+ * Registers a callback which will be called whenever a sd card will be ejected and before <br>
+ * the SDUtils_AddAttachHandler. This callback is supposed to be used to clean up any open <br>
+ * file handles before the sd card gets unmounted. <br>
+ * This is only true for future events, if the sd card is already ejected before registering <br>
+ * a callback, the callback is only called on the next ejecting. <br>
+ * <br>
+ * Any previously registered callbacks will be removed when the currently running application <br>
+ * is closing. <br>
  *
  * @param fn callback that will be called
- * @return SDUTILS_RESULT_SUCCESS on success
- *         SDUTILS_RESULT_MAX_CALLBACKS when registering the callback has failed because the
- *                                      maximum amount of callback has been reached
- *         SDUTILS_RESULT_LIB_UNINITIALIZED if the lib was not initialized properly
+ * @return SDUTILS_RESULT_SUCCESS on success <br>
+ *         SDUTILS_RESULT_MAX_CALLBACKS         when registering the callback has failed because the <br>
+ *                                              maximum amount of callback has been reached <br>
+ *         SDUTILS_RESULT_LIB_UNINITIALIZED     if the lib was not initialized properly <br>
+ *         SDUTILS_RESULT_UNSUPPORTED_COMMAND   Command not supported by the currently running module
  */
 SDUtilsStatus SDUtils_AddCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn);
 
@@ -107,9 +111,10 @@ SDUtilsStatus SDUtils_AddCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn);
  * Removed a previously registered callback
  *
  * @param fn
- * @return SDUTILS_RESULT_SUCCESS on success
- *         SDUTILS_RESULT_NOT_FOUND when the given callback was not registered.
- *         SDUTILS_RESULT_LIB_UNINITIALIZED if the lib was not initialized properly
+ * @return SDUTILS_RESULT_SUCCESS               on success <br>
+ *         SDUTILS_RESULT_NOT_FOUND             when the given callback was not registered. <br>
+ *         SDUTILS_RESULT_LIB_UNINITIALIZED     if the lib was not initialized properly <br>
+ *         SDUTILS_RESULT_UNSUPPORTED_COMMAND   Command not supported by the currently running module
  */
 SDUtilsStatus SDUtils_RemoveCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn);
 
@@ -117,7 +122,7 @@ SDUtilsStatus SDUtils_RemoveCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn);
  * Checks if a FAT32 formatted SD Card is inserted, mounted and available via `fs:/vol/external01`
  *
  * @param outStatus stores the result of the function
- * @return SDUTILS_RESULT_SUCCESS  on success
+ * @return SDUTILS_RESULT_SUCCESS  on success  <br>
  *         SDUTILS_RESULT_INVALID_ARGUMENT when an invalid ptr has been given
  */
 SDUtilsStatus SDUtils_IsSdCardMounted(bool *outStatus);
diff --git a/source/utils.cpp b/source/utils.cpp
index e112214..71dda17 100644
--- a/source/utils.cpp
+++ b/source/utils.cpp
@@ -34,22 +34,22 @@ SDUtilsStatus SDUtils_InitLibrary() {
 
     if (OSDynLoad_FindExport(sModuleHandle, FALSE, "SDUtilsAddAttachHandler", (void **) &sSDUtilsAddAttachHandler) != OS_DYNLOAD_OK) {
         DEBUG_FUNCTION_LINE_ERR("FindExport SDUtilsAddAttachHandler failed.");
-        return SDUTILS_RESULT_MODULE_MISSING_EXPORT;
+        sSDUtilsAddAttachHandler = nullptr;
     }
 
     if (OSDynLoad_FindExport(sModuleHandle, FALSE, "SDUtilsRemoveAttachHandler", (void **) &sSDUtilsRemoveAttachHandler) != OS_DYNLOAD_OK) {
         DEBUG_FUNCTION_LINE_ERR("FindExport SDUtilsRemoveAttachHandler failed.");
-        return SDUTILS_RESULT_MODULE_MISSING_EXPORT;
+        sSDUtilsRemoveAttachHandler = nullptr;
     }
 
     if (OSDynLoad_FindExport(sModuleHandle, FALSE, "SDUtilsAddCleanUpHandlesHandler", (void **) &sSDUtilsAddCleanUpHandlesHandler) != OS_DYNLOAD_OK) {
         DEBUG_FUNCTION_LINE_ERR("FindExport SDUtilsAddCleanUpHandlesHandler failed.");
-        return SDUTILS_RESULT_MODULE_MISSING_EXPORT;
+        sSDUtilsAddCleanUpHandlesHandler = nullptr;
     }
 
     if (OSDynLoad_FindExport(sModuleHandle, FALSE, "SDUtilsRemoveCleanUpHandlesHandler", (void **) &sSDUtilsRemoveCleanUpHandlesHandler) != OS_DYNLOAD_OK) {
         DEBUG_FUNCTION_LINE_ERR("FindExport SDUtilsRemoveCleanUpHandlesHandler failed.");
-        return SDUTILS_RESULT_MODULE_MISSING_EXPORT;
+        sSDUtilsRemoveCleanUpHandlesHandler = nullptr;
     }
 
     return SDUTILS_RESULT_SUCCESS;
@@ -96,9 +96,12 @@ SDUtilsStatus SDUtils_IsSdCardMounted(bool *status) {
 bool AddAttachHandler(SDAttachHandlerFn);
 
 SDUtilsStatus SDUtils_AddAttachHandler(SDAttachHandlerFn fn) {
-    if (sSDUtilsAddAttachHandler == nullptr) {
+    if (sSDUtilsVersion == SD_UTILS_MODULE_VERSION_ERROR) {
         return SDUTILS_RESULT_LIB_UNINITIALIZED;
     }
+    if (sSDUtilsAddAttachHandler == nullptr || sSDUtilsVersion < 1) {
+        return SDUTILS_RESULT_UNSUPPORTED_COMMAND;
+    }
     auto res = reinterpret_cast<decltype(&AddAttachHandler)>(sSDUtilsAddAttachHandler)(fn);
     return res ? SDUTILS_RESULT_SUCCESS : SDUTILS_RESULT_MAX_CALLBACKS;
 }
@@ -106,9 +109,12 @@ SDUtilsStatus SDUtils_AddAttachHandler(SDAttachHandlerFn fn) {
 bool RemoveAttachHandler(SDAttachHandlerFn);
 
 SDUtilsStatus SDUtils_RemoveAttachHandler(SDAttachHandlerFn fn) {
-    if (sSDUtilsRemoveAttachHandler == nullptr) {
+    if (sSDUtilsVersion == SD_UTILS_MODULE_VERSION_ERROR) {
         return SDUTILS_RESULT_LIB_UNINITIALIZED;
     }
+    if (sSDUtilsRemoveAttachHandler == nullptr || sSDUtilsVersion < 1) {
+        return SDUTILS_RESULT_UNSUPPORTED_COMMAND;
+    }
     auto res = reinterpret_cast<decltype(&RemoveAttachHandler)>(sSDUtilsRemoveAttachHandler)(fn);
     return res ? SDUTILS_RESULT_SUCCESS : SDUTILS_RESULT_NOT_FOUND;
 }
@@ -116,9 +122,12 @@ SDUtilsStatus SDUtils_RemoveAttachHandler(SDAttachHandlerFn fn) {
 bool AddCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn);
 
 SDUtilsStatus SDUtils_AddCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn) {
-    if (sSDUtilsAddCleanUpHandlesHandler == nullptr) {
+    if (sSDUtilsVersion == SD_UTILS_MODULE_VERSION_ERROR) {
         return SDUTILS_RESULT_LIB_UNINITIALIZED;
     }
+    if (sSDUtilsAddCleanUpHandlesHandler == nullptr || sSDUtilsVersion < 1) {
+        return SDUTILS_RESULT_UNSUPPORTED_COMMAND;
+    }
     auto res = reinterpret_cast<decltype(&AddCleanUpHandlesHandler)>(sSDUtilsAddCleanUpHandlesHandler)(fn);
     return res ? SDUTILS_RESULT_SUCCESS : SDUTILS_RESULT_MAX_CALLBACKS;
 }
@@ -126,9 +135,12 @@ SDUtilsStatus SDUtils_AddCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn) {
 bool RemoveCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn);
 
 SDUtilsStatus SDUtils_RemoveCleanUpHandlesHandler(SDCleanUpHandlesHandlerFn fn) {
-    if (sSDUtilsRemoveCleanUpHandlesHandler == nullptr) {
+    if (sSDUtilsVersion == SD_UTILS_MODULE_VERSION_ERROR) {
         return SDUTILS_RESULT_LIB_UNINITIALIZED;
     }
+    if (sSDUtilsRemoveCleanUpHandlesHandler == nullptr || sSDUtilsVersion < 1) {
+        return SDUTILS_RESULT_UNSUPPORTED_COMMAND;
+    }
     auto res = reinterpret_cast<decltype(&RemoveCleanUpHandlesHandler)>(sSDUtilsRemoveCleanUpHandlesHandler)(fn);
     return res ? SDUTILS_RESULT_SUCCESS : SDUTILS_RESULT_NOT_FOUND;
 }
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