How many VST Instrument instances possible?

In Cubase 8.5 & 8.0 64bit after saving and restarting my projects fail to load when I add 17 or more Korg Classic Instruments in addition to 5 other vendor VST Instruments - anybody else have this many VST’s with success? The performance meter is at 25%, there is no problem at setup. Problems only at re-opening project. At 12 instruments opening the re-opening project is fine. I am loading project with the same Korg synths multiple times, with other instruments, BFD, Piano1, HALion, Groove Agent, HSSE & Audio - Thanks for you attention. (2 Apollo’s, microKey2, Asus i7 8x40GH 64GB). Win7 pro 64bit

I don’t have similar issues.

I suggest you do a bit of testing to see if it is indeed and only the KORG plugs: start with a project with only native Steinberg plugs, see if it crashes. If not, add one KORG plugin instance, rinse and repeat and continue until it crashes. Repeat with other third party plugs too, to verify if it is only KORG or also others.

If you can bring it back to only one plugin, check if the vendor has an update, if not, you are unfortunate and will need to research further or get an alternative for the crashing plugin…

Hope this helps (btw, do you use 32 or 64b?)