WHMCS Issue Need Fixed ASAP

Job ID: 37962311

Budget: $30 – $250 USD

We recently upgraded our WHMCS from 8.8 to 8.9 and now the main page shows a spinning circle and not allowing us to use the page. I disabled all hooks, modules, and custom template but it doesn't help. Need someone who is familiar with WHMCS who can check on this asap.
Related categories: PHP Apache WHMCS HTTP CentOs