Are you trying to upload as an image rather than a document? (I did the same thing initially and got the same error!)
Hi, I'm trying to upload a pdf as a document. Others have successfully done so in the past. Are there total space limits or file size limits? If so how do we find out what they are?
Thanks for replying.
Replying to myself. I can successfully upload .docx files - and there doesn't seem to be a file size issue, but I can't upload pdf's of any size.
OK. Having realised the problem was to do with the type of file (pdf) rather than the file size I was able to find a previous thread which deals with exactly this problem.
In summary though, the problem is caused by the MIME type which is embedded in the file by the web browser. It seems there's a problem with Firefox, which is what I was using. I tried uploading a pdf with Microsoft Edge and it worked fine.