Hi @Dave_3049,

This is certainly outside of expected behaviour, the following may help to locate the source of the issue.

Most importantly we need to find a consistent means of replicating the issue, Intermittent issues are the worst but they just mean we don’t know the root cause yet or there are network issues at play.

• Is there a pattern to the size/number/naming/type of files uploaded that cause an issue.
  • check known bad items and investigate what was uploaded and see if there is a pattern.
• Is there a common browser/version of browser for the uploads.
  • Some browsers can have issues with JavaScript on upload that the form is not instructed to handle, in this case errors should appear in the console.
• Is there a common location of bad uploads that effects users? 
  • For example, users on VPN or certain offices have the issue both others do not.
• Is this issue effecting all forms on all lists? 
  • It is important to determine if perhaps this is a list/form issue so testing on another list/form will help.
  • If you have DEV/UAT environments to test this will be a great place to start.

Ultimately if you run through these steps and are not able to identify the root cause I would reach out to our support team. 

Jake

Hi @Dave_3049 
Have you managed to resolve your question?