Error: The site collection could not be restored

During the daily work, I always create a new site collections in Dev or Test environment first.  If end users are happy about it, then I take a backup and restore it to Production server.

However, a few days ago, I start to get the error below during the site collection restoration.


VbackupRestore::RestoreSite, failed HR detected: -2147023893

The site collection could not be restored. If this problem persists, please make sure the content databases are available and have sufficient free space.0x81020099

Error Category: InvalidData    Target Object  Microsoft.SharePoint.PowerShell.SPCmdletRestoreSite  Details  NULL  RecommendedAction NULL

Obviously there are some objects in the destination database which have the same GUID as the objects in backup file. But, how can a new site collection has objects conflict with existing site collections?

Then I recalled that I created a customized site template for new site collections. I thought that new GUIDs were created for all objects when we choose old site template --- I was wrong.  Site definition is not site template. Some object GUIDs are not been replaced by new GUIDs!

So, no choice. I have to recreate the site collection from scratch in Dev environment, then deploy it to Production. Any way, if there is no coding, that's normally easy and simple.