Far as I've seen into the PAYDAY 2 modding subforum, lots of people are posting that BLT doesn't work anymore, or that the game crashes for no reasons.

What you need to know, and as OVERKILL_Tobias said, the mods that were supposed to partially fix/remove the desync will most likely not work anymore.
List of the most obvious examples:

• Velosync
  
• Poco HUD with the desync resolve option
  
• Adaptive Resync
  

If you have any of these examples above, you need to remove them. They are not necessary looking at how the game is now anyways.

If it still doesn't work, you should first reinstall BLT to see if the problem is the hook.

You can get an up-to-date version of BLT here : https://github.com/JamesWilko/Payday-2-BLT.
Specifically on the Releases tab: https://github.com/JamesWilko/Payday-2-BLT/releases
Extract the content of both archives to Steam/SteamApps/common/PAYDAY 2/.

Double check if you also have BLT's dependency, which is x86 2013 C++ Runtime.

If the two solutions above didn't helped, you should start to remove either all your mods, or taking them out one by one to find which mod is causing your issue. Keep in mind that some mod_overrides are causing crashes too. Don't forget to check there as well.

If you still have issues, feel free to post here. I'll see what I can do to help you.