BizTalk Konsole stops working with Error IDS_ERR_FIND_SCHEMA

I wanted to update a BizTalk assembly in which a schema had change its name. To make it simple, I chose to use the "modify" option inside the BizTalk administration konsole. I then run into the following error:

Schema referenced by Map 'XXX' has been deleted. The local, cached version of the BizTalk Server group configuration is out of date. You must refresh the BizTalk Server group configuration before making further changes. (Microsoft.BizTalk.Administration.SnapIn)

------------------------------
For help, click: http://go.microsoft.com/fwlink/?LinkId=47400&ProdName=Microsoft+BizTalk+Server+2013&ProdVer=3.10.229.0&EvtSrc=Microsoft.BizTalk.ExplorerOM.Resources&EvtID=IDS_ERR_FIND_SCHEMA

I first tried to refresh the group but this did not help. Instead, I could not even open the application list.

Luckily, the error message told which map missed its schemas.

We could solve this problem (thanks, Christian!) by correcting the message type inside the BizTalkMgmtDb table bt_DocumentSpec where it was still stored with the old name (so it was not updated during "modify" action).

So if you update an assembly, in which a schema changed its name, you have to install the assembly from the scratch.

But if you already have run into that problem, open table bt_DocumentSpec and check whether the docspec_name is correct there.