I’m also having the issue with Fyber adapter sdk download. I went through their website and it’s clear that they simply changed the download location, which should be simple enough for developer to solve if he bothered, but it looks like he abandoned the app. I’ve been trying to contact him or anyone in the team, with no luck whatsoever.
The main problem is that the GameDNAInstaller plugin is not clean - it actually has a .exe file in it that does some of the magic and we don’t have line of sight of the code in that executable. That means that we can’t figure out where the files are stored nor adjust the download location manually. Had I known that I wouldn’t have spent quite a lot of cash buying this company’s plugins only to be left unsupported not long after making the purchases.
The way I eventually solved the issue was by opening a very old engine installation (4.20), copying the plugin directory Source\ThirdParty into the new installation. I also forced the version change in the .uplugin file to 4.24 (dirty work - I haven’t checked or tested the code, just changed the version described in the file). The result was a bunch of warnings but no errors and the installation actually worked. This clearly isn’t sustainable as the plugin will eventually break if unsupported, so I’m studying the code to try to maintain it manually myself given circumstances.