How do you Disable or Enable creation of Sandbox projects?
You can change the value directly in the TAC database.
Run the following command in your database (this is for MySQL, your syntax may be different):
UPDATE `yourdatabasename`.`configuration` SET `value`='false' WHERE `key`='remoteconnection.metaservlet.enableSandboxProject';
Or you can manually navigate to your database, to the table `configuration` and change the row 'remoteconnection.metaservlet.enableSandboxProject' 'value` to false or true.