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Path.GetFileName() - now handles ArgumentException and PathTooLongException
File.GetLastWriteTime() - now handles ArgumentException, UnauthorizedAccessException, and PathTooLongException
Background file operations - wrapped entire task with exception handling for the same exceptions

Why Path.GetFileName() and File.GetLastWriteTime() will call the ArgumentException?

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Path.GetFileName() - now handles ArgumentException and PathTooLongException
File.GetLastWriteTime() - now handles ArgumentException, UnauthorizedAccessException, and PathTooLongException
Background ...

These .NET methods throw ArgumentException when they encounter invalid path characters:

Path.GetFileName() throws ArgumentException when:

• The path contains Windows-illegal characters: < > " | ? * :
• The path contains characters defined in Path.GetInvalidPathChars()

File.GetLastWriteTime() throws ArgumentException when:

• The path contains invalid characters (same as above)
• The path is malformed or contains invalid character sequences
• Internal Windows file system permission checks fail due to illegal characters

The original crash from issue #1734 showed this exact stack trace:

System.ArgumentException: Illegal characters in path.
   at System.IO.File.InternalGetLastWriteTimeUtc(String path, Boolean checkHost)

These exceptions occur because Windows file system APIs strictly validate path characters before performing operations. When QuickLook receives paths with problematic characters (e.g., from shell extensions or other sources), these methods fail immediately rather than gracefully handling the invalid input.

The defensive programming approach prevents crashes by catching these exceptions and providing fallback behavior instead of letting them bubble up unhandled.

Unimportant exceptions, keep throwing errors