Not being able to select the background or foreground with Primatte is typically related to one of these reasons:
- Primatte is not selected (Premiere only)
Click the words Primatte Keyer in the Effect Controls panel and try selecting your clip's foreground/background once again.
- Layer Controls are disabled (After Effects only)
Head into the View menu of After Effects and select Show Layer Controls, then try once more.
- The Preview is not in Full resolution
Because Primatte is trying to work directly with frame and clip information pulled from the preview panel, if the preview panel is not in its full resolution (i.e. it's in Half, Quarter, or Third), the plugin can have issues sampling the frame. Switch it to Full resolution.
- If the preview resolution is set to "(Full)" (i.e. Full had been selected by the Auto setting) but you are still having this issue, try selecting Full directly to check if that helps.
- File permission issues (Mac only)
Repair file permissions across your Mac using the Disk Utility program, then see if your issue persists. If it does, contact support for further instructions on how to repair file permissions on the directory where the plugin files get installed into, which varies per host/version.