OK, here's my problem. I'm using Sonar Producer X2 64 bit on a Windows 7 PC.
 
I tried to scan a new plugin, and then all my plugins stopped working.
 
I tried to do a re-scan of all my plugins. All I got was  repeated error messages that said 'Failure to Load Proxy.'
 
I think it might be a Jbridge problem, since I've been using Jbridge for 32 bit plugins.
 
Can't re-scan plugins now. It's a mess. 
 
I'm just a bass player, not an engineer, so I'm pretty lost. Not the most technical person. 
 
Thanks.

Get rid of the new plugin via uninstall (hopefully) so it will not hang up scan and then rescan your plugs.

Yeah, I tried that. No go.

In Sonar, are you doing a vst RESET before the rescan?  The former is really the critical step, and the pair should be thought of as parts of a single function.
 
Then you can follow with the jBridge scan.

I have no idea what that even is. I'm really just an idiot bass player.

https://www.cakewalk.com/Support/Knowledge-Base/2007013315/SONAR-X3-Full-VST-Rescan-Recommended-for-Upgraders