Try this solution:
Check the path and "Start in":
Task Properties > Actions > Edit.
Make sure the path in "Program/script" is correct and fill in the "Start in (Optional)" field with the path to the folder where the script is located.
Set the highest privileges:
Task Properties > General > check "Run with highest privileges".
Check account permissions:
Make sure that the account under which the task runs (in the General tab) has full permissions to the target files and folders.
Use exit /b 0 in batch scripts:
If the error comes directly from the script, add exit /b 0 at the end of the script to suppress the error if nothing is wrong or to allow the script to exit correctly.
Summary: Error 0x1 is often about file unavailability or permissions, so checking paths and rights is key to resolving it.