General

Order was not created. Reason: This product is currently out of stock

Check how to resolve “Order was not created. Reason: This product is currently out of stock" error. 

#selling #out of stock #order #quantity
Mage registry key already exists

Read what to do if "Mage registry key already exists" error occurred after the Module installation/upgrade.  

#cache #compilation #installation/upgrade
Order was not created. Reason: Please specify a shipping method

Check how to resolve "Order was not created. Reason: Please specify a shipping method" error.

#external tool #shipping #order
The listing was locked by another process

Learn how to resolve “The listing was locked by another process. Please try again later”  error.

#m2epro listing #locked listing #synchronization
Currency Changing is not allowed and You are not able to change Payment Currency

The errors may occur during the Subscription activation process if the data (value) has been cached. 

#clients portal #subscription activation #payment currency