Having betterportals-1.12.2-0.3.7.7 and CubicChunks-1.12.2-0.0.1055.0-SNAPSHOT-all installed together results in the game not loading properly.
The process javaw.exe will start, but the game window won't appear.
Used Forge version is 1.12.2-forge-14.23.5.2854.

Installing both mods separately solves the issue.

Better late then never, but I believe due to some error you have to make sure better portals loads after cubic chunks, which you can do by making it further alphabetically. At least, I remember being told to rename the jar file to dbetterportals.