Topaz & DxO NIK Collection Greyed Out

After returning from vacation, I booted up and opened PS to do some work, and mysteriously these plug-ins are greyed out and unavailable. To my knowledge I didn't update PS; although I did purchase and install the new Nik Collection 4. I've tried reinstalling the plugins, reopening PS, and even restarting my computer, but nothing seems to work. Help!