@gaurav_sharma18Not sure if you already compared. Please compare the PHP configuration of both server. That need to be same for example PHP version and all the modules enabled on old server must be enabled and configured on the new server as well.
You can also look into <Magento Root Direcotry>/var/report folder to see what exact error you are getting to resolve the issue.
Other issue can be of the permission. As you recently moved from server A to server B make sure to set the proper permission on all the files and folder to have your Magento working.
Hope this will help you in debugging the issue further and resolve it.
- Tarandeep
Problem solved?Please give 'Kudos' and accept 'Answer as Solution'.