Thanks for the offer, however i think i may have found the issue. I decided to go brute force and go back to the onprem version which is 7.10 (cloud was 7.10 and had the same issue). I cloned the workpad and went through deleting elements, export/import to try and find if anything in particular was causing the issue.
The element that causes the issue was a timelion. The index it was using was renamed in the cloud version, i created a new workpad and added the saved timelion element and it did the same with the below error. Within the new canvas i cannot see timelion elements now.
responseText is only available if responseType is '' or 'text'.