Did you find a solution? Because i'm having the same problem... I mean, i can see the home page but everytime i have to comunicate with a controller and going to another url, i have a 500, and no more information, no logs, no laravel log... i don't know what else to do. I tried making an example controller with a simply method for try in the IONOS host, but it didn't work. Everything works locally but not when i try in IONOS. I tried modifying the .htaccess as your answers say but it didn't do anything :(