[2019] I lost Bear Form skill

What version number do you see in the top left of your screen?

If this is a character that did not have 25 points in Druid before 0.7.4 released, this is working as intended, because Werebear Form has become exclusive to characters who Mastered into Druid.

In 0.7.3, you became a Mastery Class as soon as you invested 25 points into it and then clicked the “Ascend to (class name)” button on their passives panel. In 0.7.4, you become a Mastery Class after completing a quest that is given to you when you first reach the End of Time.

Please try talking to Elder Gaspar in the End of Time, he should give you the Mastery Quest. There’s a bug affecting how many enemies you will fight, but this will be addressed in a bug fix patch soon.