Scenario: you have created a BizTalk 2006 R2 solution (using Visual Studio 2005) on one machine and just copied it to another one to continue work and deploy. The rebuild goes fine, but when you try to deploy the solution, the error message comes:
"The database or the database version is incompatible with the installed version of this product"
Probably you had different versions (mostly SP of SQL Server) on your source and target machine.
What to do?
1. Close the solution.
2. Open Explorer and delete *.btproj.user files.
3. Reopen the solution, rebuild and deploy it.