C# Error CS2021 – File name ‘{0}’ is empty, contains invalid characters, has a drive specification without an absolute path, or is too long

C# Error

CS2021 – File name ‘{0}’ is empty, contains invalid characters, has a drive specification without an absolute path, or is too long

Reason for the Error & Solution

File name ‘file’ is too long or invalid

All file names passed to the C# compiler must be no longer than _MAX_PATH (defined in a Windows header file). The compiler will give this error in the following situations:

  • A file name (including the path) is longer than _MAX_PATH.

  • The file name contains invalid characters.

  • The file name contains wildcards where wildcards are not allowed (such as in resource file names).