Is there a way to restore source engine after update from launcher?

I got 4.20.2 source in Epic Games folder and hope they fixed physics replication in 4.20.3. So I used a launcher to update. but it seems like it broke source version, because “error LNK2001: ??? ??? ???” returned. Is it possible to fix the engine without reinstalling and recompilling all over again? It took me 45 hours last time.

Negative. Reinstall, endure, overcome.