Atsuko,
Like Nigel said, make sure the PACE service is running. Otherwise everything will crash. Depending on your OS, can access what is running either thru the task manager or the control panel under administrative tools and then services. From there, start PACE. The new improved "fix" is corrupt about starting PACE. Does not work here. I've tried on win XP, 7, 10, and PACE is dead in the water without a manual start.
My individual problem is with a UVI sound bank that shows it is activated from the PACE side, but computer says unauthorized. No reply or help from PACE, and UVI said I'm just flat out of luck. Thanks for the non refundable purchase however.
Was able to get the Waves deal on GTR and CLA amps. Neither would install. Error message on the computer said that PACE is corrupt and has to be reinstalled, go to the website and download the latest version. Latest version says it can't install because PACE is already installed. Dead in the water with no help from anyone, and worst thing about it, realized nobody cared.
Took a couple minutes to download an illegal crack of GTR. Installed fine and no problems. I can live without the amps and taking it as a minor economic loss.
Maybe someone else with more knowledge can chime in here, but in Reaper, the loading of plugs is in a vst ini folder. Got to be something similar with Sonar. The last entries are the last plugs installed, and can cause a quarantine of the failed plug. Cleanest approach is to open the file and delete the last entry, then rescan with a fresh start, after PACE has been manually started.
Hope this helps,
John