Zend certified PHP/Magento developer

Magento 2.3x Multi-Vendor Marketplace, The Vendor Panel is showing a blank white page

I had upgraded the PHP version from 7.1 to 7.2 and also the Magento2 version from 2.2 to 2.3x community version, since then the Vendor panel is not loading and is just showing a blank page. If I disable the separate dashboard, the panel loads in the customer account.