I had the same problem recently and contacted tech support. Here’s the response:
The most likely issue that a third party plugin is causing the problem. Personally, I do not use the Update option because it does not show what is being initialized as well as the opening splash screen.
To add a third party plugin go to Devices, Plugin Information, VST 2.x Plugin Paths. Add the specific folder path of your plugin (not the entire C drive, as that will cause a crash), then shut down and restart Cubase. Cubase will then rescan for any plugin it can load. Thank you."
Im currently on Win7x64 C6.5.5 and i havent experienced any problems regardless of the error message. I am also running some free 32bit vst’s and they’re running smoothly.
You can also check out JBridge if you prefer using a different bridging method but i dont know how up to date they are.
Hope this helps.