After effects mask bug

[faaaakthis]

My after effects makes a white shape in the corner of a mask. why ? how can i fix this? it is super annoying .

There is only black under the mask, and i have no white background or files under.

the glitch appears on random frames, and if i add 1 more point to the mask, the glitch disapears on the frame, but appear on another frame .

Add 2 more points to the mask and the glitch appears again.

what is this ?

[Dave_LaRonde]

Try purging memory & caches.

[Kevin-Monahan]

faaaakthis,

Did Dave's advice assist you? Let us know.

Thanks,
Kevin

[Roland Kahlenberg]

It's hard to tell what the issue is without seeing the mask vertices. The only issue I assume is with overlaps in your mask's vertices. So, take a look if there are overlaps/crossovers.