Im getting some weird issues since upgrading to SS 2.4.1 (Can confirm the same with 2.4.0 as well).
I currently have DOM r403 and SWFUpload r414 in use.
When uploading files using the FIleDataObjectManager i run into the issue where I am unable to upload any files. From what I can tell this is due to the line 587 check
When I remove this all works fine on dev machine but logs me out (and no file upload) when on staging (same as the Live server).
After re-enabling the above code and turning debug on for SWFUpload gives me this output.
The strange thing with this is it sometimes works (That is the progress bar does goes up and told that upload was successful, so additional debug lines) most of the time this doesn't work and just outputs what is above.
I am unsure why this has broken as I recall this working at least for 2.4.0 (cant confirm with 2.4.1) but even going back it seems to have broken somewhere.
The only thing I have changed is on line 393 of FileDataObjectManager.php which was throwing an error when using multiple FileIFrameFields
$total = isset($_POST['totalsize']) ? $_POST['totalsize'] : ( isset($_POST['uploaded_files']) ? sizeof($_POST['uploaded_files']) : 0 );
The above code seemed to fix that.