Skills points bugged after transferring save

As I transfer my save from celtic doom to the quest gold classic, I found out that I'm not able to add points to either my primary skills or other skills (even i have 500 points available), what should I do?

Btw everythings works normally with my save in celtic doom extension pack

The natural skill limit is 100 in Classic. In the standalone expansions the skill limit is much higher.

You are not supposed to transfer characters started in a standalone expansion to the base game. All standalone characters are boosted to be able to play through the expansion. This boost can vary between expansions, there is no rigorous calculation behind it.