7-5-8. System error occurred on Deploy

Q.

System error occurred on Deploy.

A. 


When Full test is selected as the deploy option, all tests will run in Salesforce (even those of existing Apex Classes and Apex Triggers unrelated to SkyVisualEditor). The above message could be caused by unrelated existing Apex code. If another administrator is actively working on your environment please try again later or deploy to a sandbox environment first and migrate to the production environment as a change set.