Black Slots on Material Editor

Hi guys, i am learning 3ds max and found out Corona just a few days ago, it seems awesome and i want to try to learn more, however there is this problem with my corona slots on the material editor,the slots appear all black and i can’t preview anything on them.

I already reinstalled everything, including max and it happened again. Am i missing something or is it a bug?

Screenshot provided for analysis.

Thanks in advance.

Found the problem digging the forum.. newb error.