What causes the 83% bug?

Anything that doesn't fit into other topics goes here!
So I just got the NI Kontact 5 Player last night. The standalone worked fine, it loaded in LMMS nicely, and it played without any huge CPU spikes. Yet when I loaded the test file it saved it in, the project loaded to 83%, then stopped. Now I know this isn't anything new, but does anybody know what causes this? Thanks
Yes, Thats when the chunk created by the vst is absurdly humongous.
Its one of the reasons that you need to go through the vst-tests:
https://lmms.io/wiki/index.php?title=Wo ... d_problems
Before using vst's in real projects
The wiki also explains how to fix the hanging project.