I noticed others had a similar issue that I'm having, although I don't know if the cause is the same.
ISSUE:
Running in a brand-new SANDBOX save file, if I launch a craft (even a super simple one with just a probe core) and revert to VAB/SPH, the game soft locks. None of the buttons work and I am unable to change scenes.
My log prints that a bunch of Scenarios are unable to be loaded.
If I remove this mod, the game works as intended. Additionally, I have a career mode where this issue does not occur (at least to my knowledge).
MY WORK AROUND:
My sandbox had the stock setting "Enable Comm Network" disabled. If I enable it, the game no longer soft locks.