Troubleshoot Web Application Hanging Problem in PhP

Job ID: 32757683

Budget: ₹1,500 – ₹12,500 INR

We have our own developed ERP software. We used Php in Codeigniter and AngularJS.
We recently migrated this from PhP version 5.8 to PhP version 7.2. This is when we started getting the problem. When multiple users logged in system is keeps on hanging so everytime we had to restart the apache then its working for sometime. We didn't get any errors in the backend.

I am looking for someone to look at this problem and fix it. People with adequate skills only requested to drop a message.
Related categories: PHP JavaScript Software Architecture MySQL AngularJS