The file field cannot accept long file names

hi.
The file field cannot accept long file names and displays an incomprehensible error in response to a user who sends a file with a long name. I want to use cb conditional to validate the file name so that if the submitted file name is too long, I can display the appropriate error to the user.
1- What is the maximum file name?
2- From which variable or substitution should I get the file name?

The file field cannot accept long file names and displays an incomprehensible error in response to a user who sends a file with a long name.

Define a long file name? Find it hard to believe people are actually uploading files that have a name so long it hits system filename limits. You might be trying to workaround an issue that effects 0.1% of your users if that.

1- What is the maximum file name?

There isn't one. You're hitting a server limit.

2- From which variable or substitution should I get the file name?

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