Can't attach files to "modern" list form, but classic form works fine?

Occasional Contributor

Our Sharepoint Online users get an error when they try to upload attachments using a list form. But, they only get an error when using the Modern form.  If I switch to the Classic layout, attachments upload and send successfully.

Here's the error we get when uploading attachments on the Modern form:



The error appears after the user clicks "Save".  (Also odd—the content of the form will save to the list successfully, unbeknownst to the user who will keep clicking the save button—not realizing they're creating multiple entries.)


think this may be a permissions thing, since admin-level users don't experience the error.


Here's screenshots of the current permissions settings for users of the form. Is there a permissions setting that would impact attachments to Modern list forms but not classic ones?







1 Reply
best response confirmed by SophieSue (Occasional Contributor)

After some trial and error, I found that I had to modify the permissions level used on this list. 

In my case, I use a custom permissions level just for our lists. I had to ensure "Edit Items" was checked under the "List Permissions" section of the Permissions Level settings.


Not sure why this impacts classic and new-style forms differently, but there you have it.