Unable to add multiple files to Invoice during creation 1.5.2

There seems to be few bugs with adding files to Invoices.

  1. During invoice creation Multiple Uploads will fail. 1st file will upload 50/50 of the time, and the other will fail.

  2. During invoice creation a file may show up as Uploaded but after saving the Invoice the file will be missing.

I can upload first file, but second one crashes.
It gives me a 403 error.
The filename of the second file differs from the first one.

Any Ideas?