Textured Brushes not working

For some reason Toon Boom now won’t display textured brushes. When I open a new file or load an old one, all texture presets show up as black rectangles, and when I try to use them or change textures on another brush and use that, it doesn’t work, shows a pixelated black brush that defaults to an untextured line. I’ve never seen an error like this before. I’m using Windows 10 on a Dell laptop.

Which mode graphic card is installed?

The issue appears to have resolved itself. Thanks!

Critically - help needed. I’ve got the same problem, but rectangles are white. I’ve just reinstalled windows 10. I’ve no idea what went wrong. I can’t use textured brushes. HP Envy 15-ae104ur laptop, and cards - Interl (R) HD graphics 520 and GeForce GTX950M. What can be done with this problem?
Upd:
The problem was solved by reinstalling the program. Destination folder was C/Program Files (x86) by default this time.

Try setting the graphic card of the system’s power features to provide
“Maximum Performance”. If there are two graphic cards installed make
sure the dedicated graphic card is the one that’s being used instead of
the onboard card.

If you need help with setting the graphic card properties, contact
support to remotely connect to your system to assist.

I have the same Problem, I installed the Harmony 16 Premium Trial Version on my Mobile Studio Pro 16.

I recently installed Harmony Advanced 20 (upgrading from 16) and I’ve encountered this same issue. The Pre-packaged textures won’t load (they all show up as red&white boxes) and clicking on them changes the line art to the same, dashed line for each title of texture.

I have adjusted my graphics settings, updated the drivers, but still no solution.