a!fileUploadField() does not have any built-in limitation that prevents uploading .zip files. If .zip is allowed in the Admin Console > File Upload settings, the component should accept ZIP files.

The error "Files without extensions are not permitted on this system" typically indicates that Appian is treating the uploaded file (or a file inside the ZIP, if compressed-file inspection is enabled) as having no valid extension. It is not a documented limitation of a!fileUploadField().

Verify the following:

The ZIP file is valid and not corrupted.

The file actually has a .zip extension (not a hidden or double extension).

If "Apply upload settings to contents of compressed files" is enabled, ensure all files inside the ZIP have valid, permitted extensions.

Try uploading a newly created ZIP containing only a simple .txt file to determine whether the issue is specific to the archive.

If a simple, valid ZIP also fails despite the correct Admin Console configuration, it is likely an environment-specific issue , try the same on different envionemnent

#FileUploadComponentLimitaions

RE: #FileUploadComponentLimitaions