You can use the Spira Project Backup & Migration Tool to move projects between one instance of SpiraTest and another pretty easily. However there is a known issue that can sometimes occur if you have deleted custom properties.
Customers running Spira v5.0 or v5.1 may experience an issue where the system will let you create test case folders that point to one of their children as parent. This causes an infinite loop which will break the system. This article provides a solution to fix the issue (though we recommend upgrading to v5.4 to prevent it happening in the future).
Sometimes when you try and run certain reports you may get an strange error message "The passed in report ID or report format ID does not exist". This message is unfortunately a red herring, and there is a different reason for this error.