All Plugins Reset In All Tracks?!

I am about to lose my mind.

Mixed all weekend. Listened over and over all weekend. Open tracks today, and all of my plugins are either gone, or reverted back to ones I used ages ago. SOngs are there, mixes are there, volume and pans seems to be OK.

What is going on??? I was using snapshots, checked my old ones and they are all affected! All the dates for the session files are correct too. How can I recover these?

OK, sorry this actually is a result of the reinstall I had to do explained in another thread. As part of the reinstall, I had not re-configured my custom plugin path. So, none of my plugins were being loaded. All good now.