Planet/Star System Expansion Mods Only Launch Once Per Game Install

[VaSIMR200]

Might be a problem with my computer, but as the title says. For all planet mods i've tested (GPP, OPM, GU) the mod will only successfully launch once per instance of the game, then gets stuck at the end of game load (expansion loading complete).  Don't have any logs to show for it as it does not crash, but can pull them if there is another way.

Symptoms:

 - Occurs whether the mod (+ dependancies) are alone or with any number other mods, seems to have no affect assuming there aren't other conflicts.

 - Occurs with manual and/or CKAN install.

 - If I unpack another game instance from .zip and reinstall mods it will launch just fine, but after closing it will not launch again i.e. get stuck as mentioned. To elaborate, if I 'burn' a GPP launch, I can then remove it and install OPM. It will then launch once, but not again. Can continue for other planet packs.

Possibly linked, can't lanch KSP from the application, have to run unix executeable directly but this is no quandry alone.  No noteable related issues with any other mods, and Kopernicus seems to work fine without the planet packs. Can't get easy access to older 1.12 versions to try, but happy to if there is a legit way to get them. I have used this OS install for many ksp versions since 0.90, so maybe the game files are getting muddled? I don't mix them intentionally, keep them as they are in seperate directories, but its a theory if paper thin. Running KSP 1.12.3 on Mac OS, non-steam. 

Thanks for your considerations, first time poster on the forums here despite playing for a long time.