I allready had checked laravel.log and it seemed, that nothing was written there, when the error occured.
After reading your response I did some more tests and found out, that I had a problem in writing to the logfile on my Test-Server.
So I deleted laravel.log and after that I didn't get http 500 any more.
Instead the following error was reported:
ErrorException in FilesystemManager.php line 174:
Use of undefined constant FTP_BINARY - assumed 'FTP_BINARY'
Some more google-research told me, that this is a Problem with php 7 on windows.
Seems, that the extension is not enabled by default in php.ini
As he said: "Some more google-research told me, that this is a Problem with php 7 on windows. Seems, that the extension is not enabled by default in php.ini"
in your php.ini there will be a line like:
# extension=ftp.so
uncomment that line (or add it if it wasnt there yet). The extension should already be on your server, just not pre setup in the php.ini file