A recent Windows Update has been causing problems for GravoStyle, CorelDRAW, Adobe Illustrator and other programs that effectively use the printer/plotter driver for the L-Solution engravers (e.g. LS100). Since GravoTouch communicates with the engraver differently it is NOT affected. If you're getting a "Bitmap error" message that pops up when sending a job, a solid rectangle engraves (or shows up on the Preview in GravoStyle) where an imported PNG or JPG should be, or you get an "empty" file (a zero time job that does no actual engraving / the Preview in GravoStyle is completely blank) then you'll need to remove the offending update from your computer.
A quick way to remove the update is outlined in this PDF: How to Remove the Windows Update. For recent Windows builds (20H2 and probably 2004), the update is KB5000802. For older Windows builds (e.g. 1909), the update is KB5000808. You'll probably also want to pause Windows Updates for a while so that the update does not automatically reinstall itself. Open the Windows Settings app, click on Update & Security, and click Pause updates for 7 days (or click Advanced options to pick a longer amount of time to pause).