There are limits on file size: https://sourceforge.net/p/forge/documen ... ize-limits but this is probably not your problem. 15.5 MB should not be a problem.
Maybe it's related to this: https://sourceforge.net/p/seeddms/discu ... /133a634a/
I don't know how sourceforge is setup but maybe these instructions can help: https://popart-studio.medium.com/what-i ... 07fffdcc92 (heading "Modifying the PHP ini File")