The season manipulation command doesn't seem to respond and can sometime crash a few packs I've tested the mod in.

Assuming the issue is abadoned by the OP, and noone else is experiencing similar problem.

Can you please specify which packs did the mod crash in? Or even better, could you please post the crash report (put it here)? It would be a lot easier to know what has really happened.

Also, the season command does not always visibly take effect because how minecraft mechanics work. To fix this, press F3+A (reloads all chunks).