When I try to do "Update model from database", I get the following error:

An exception of type 'Microsoft.VSDesigner.Data.Local.ConnectionStringConverterServiceException' occurred while attempting to update from the database. The exception message is: ''.

I searched this error, and I find a reply from Jiri from about a year ago that says, "DDEX not installed correctly."

I then performed the following steps:
1) Uninstalled the Firebird DDEX provider and the Firebird ADO.Net provider
2) Replaced machine.config in the following folders with the machine.config.default file:
3) Reinstalled ADO.NET provider from NETProvider-
4) Reinstalled DDEX provider from DDEXProvider-

However, I still get the same error.  I can open the .EDMX file and view the entities, but I cannot update the model from the database.

Here is my connection string:
metadata=res://*/TRS11Model.csdl|res://*/TRS11Model.ssdl|res://*/TRS11Model.msl;provider=FirebirdSql.Data.FirebirdClient;provider connection string='initial catalog="C:\Program Files (x86)\TRS11\Data\DATA1100.FDB";user id=sysdba;password=masterkey;data source=localhost'

The database path, userid, and password are all correct.

Does this still sound like an issue with DDEX not being installed correctly?
If so, what else should I do to install it correctly, if my above steps are not sufficient.