Invalid File Name when submitting form to SharePoint List

Hi , We are experiencing issue when few users are trying to submit the List form. Can you please let us know .

I have tried caching the browser and resetting the form and re importing form which didnt work for us.

Here is the error

Invalid file name. The file name you specified could not be used. It may be the name of an existing file or directory, or you may not have permission to access the file

Thanks