Oh, noooo. You got most popular developer error 🙂
Firstly, No despair – say “Yes, I CAN”, and concentrate on possible errors.
Show all errors (how to show all errors/warnings/nootices in php)
Also, you can do “fast debug” in main parts of you code (Sure, use die() command but very carefully)
Firstly check .htaccess file on strange symbols or sentences.
Also, if you using POST method with uploading files then check php settings in php.ini (max_post_size, max_executing_time…)
Standard Apache logs dev finiding here:
nginx logs here:
Also, some popular frameworks logs folders:
– Yii errors logs path
– Laravel error logs path:
Final step: If the preceding tips do not help and you still have 500 error. Please try again to search answer in the search engines)