Http 500 error

SuiteCRM version: 7.11
php version: 7.1
MySQL version: 5.6.43

My site is working normally, but when I enter an opportunity and click the save button, it is redirected to a page with http 500 error, but the opportunity is saved normally.!

It could be the server is not assigning enough resources to SuiteCRM.

Check here for some tips:

https://docs.suitecrm.com/developer/performance-tweaks/

You can also check your logs for more info.