This might help you:
Drop and re-create your site's cache
If you suspect the problem is caused by that your site's cache rebuild process was not completed properly, you should try clearing your store's cache and running the cache rebuild process a new.
Normally, cache rebuild process takes place when you apply a core upgrade, install a new module, enable/disable an installed module, or manually launch the cache rebuild process by selecting System settings > Rebuild cache in your store's Admin area. If your store stopped functioning after one of those actions, chances are high that is because of problems with your site's cache. There are quite a number of reasons why cache re-generation may go wrong for your site, one of the most popular being closing the page where the cache rebuild process is being executed. But no matter what caused the problem, you can try to resolve it using one of the following methods:
Access your store using a link similar to the following:
https://www.example.com/x-cart/admin.php?drop_cache&access_key=XXXXXXXXXXXXXX
Replace the portion "../x-cart/" with the actual address of your store and use your actual Safe Mode access key instead of XXXXXXXXXXXXXX. The Safe Mode access key can be copied from the file var/data/.safeModeAccessKey in your X-Cart installation folder or from any of the two reset links that were sent to your site administrator mailbox after X-Cart installation (The message subject reads "Soft and Hard reset links for your store!"; for X-Cart versions 5.1.8 and earlier the subject was "New safe mode access key has been generated!").
When you use this link, your existing site cache is dropped, and the cache rebuild process is launched automatically.
Delete the folder var/run and the file var/.rebuildStarted in your X-Cart installation folder and go the your store's Admin area. X-Cart will detect the absense of cache and will automatically launch the cache rebuild process.
For More:
http://kb.x-cart.com/display/XDD/What+to+do+if+you+cannot+access+your+store+and+it+says+we+are+deploying+new+changes