Hello. Please excuse me, I'm new to this forum. It took me a lot of work to deal with the problem of your mod, but I was able to understand what the error was.
Only one of your mods is installed on a fresh game 1.12.3
in the log it [ERR 03:17:36.697] ADDON BINDER: Cannot resolve assembly: KSPDev_Utils.2.6, Culture=neutral, PublicKeyToken=null
this post helped Fix "ADDON BINDER: Cannot resolve assembly" errors in log by mwerle · Pull Request #357 · S-C-A-N/SCANsat · GitHub
@linuxgurugamer said an alternative way to fix this issue is to ensure that the dependant mod has a higher filename (eg, rename it to "+SCANsat.Unity.dll") to ensure it gets loaded first; not sure if that might cause other issues. Seemed a bit of a hack which is why I investigated the "proper" solution.
if you change the name to +KSPDev_Utils.2.6.dll everything works fine