I think it has something to do with the issues mentioned on this page;
https://github.com/ian-cox/Kirby-MinifyHTML
I did disable all plugins, the problem remains… but I guess it’s something like that.
- edit - Indeed this plug-in did corrupt the downloads; I installed a fresh version of Kirby, everythings works… I install the plug-in; downloads became corrupt.
I decided to remove the plug-in and switched to Kirby KRB - which has a minifier that “respects” forced downloads (so no minifying).