Hi,
Looks like PPG2 might be a Waldorf synth VSTi. Make sure there isn't some pop-up window hiding that you need to click OK on.
If the problem persists, here's a file that will turn off the "Load VST..." option in Plug-In preferences. Download the file, right-click to extract it, then run the .reg file that's inside. Start up Mixcraft and go into Plug-Ins preferences. Turn back on the option to load VSTs, then click Edit VST/VSTi Folders and remove any folders that don't have VST in the path, along with any other folders that aren't your audio VST plugin folders. Save that, then click on the File menu and select Manage Plug-Ins. Un-check PPG2 and any other plugins you're suspicious of. Click OK to save, then restart Mixcraft and see whether it loads.
If this doesn't help, I'd want to see your log file.
Greg