Custom file types still rejected on upload
Custom file types added in the plugin are still rejected by WordPress with a not allowed error on upload.
Tier I · Proven The best-established problems.
19 public reports · first reported 1 July 2021 · last reported 25 January 2026
What's going wrong
Many site owners add extensions such as gpx, kml, step, dwg, docm, java, sh and tar.gz in this plugin, save the settings, and then still see WordPress say the file type is not allowed. Some report the error only for uppercase extensions, others for files that worked before a PHP or WordPress update. Owners of engineering, mapping, outdoor and ecommerce sites are typically affected because they need niche formats. The plugin lists the types, but the upload check still fails, and owners often cannot tell whether the MIME type or the extension is wrong. There is an opening for a tool that checks each type against real uploads and explains the failing part.
AI-assisted: written with the help of AI from the reports.
Products affected
File Upload Types by WPForms.
Related problems
Who has this problem
1 business found.
Unlock them at the top of this page — $19.
All sales are final — no refunds.
Each business's name, the address it published, and the page it was published on. Paid through Stripe; you get a private page to bookmark, with a CSV download.