Under View the explorer function is grey and I can't uncheck the box when I click the explorer button on the bottom both boxes are blank. this just started today, but I've been using it earlier today with no problem.
You could try and uninstall Acid Pro using free Revo uninstaller and also make sure to update all your hardware drivers and windows updates before reinstalling Acid.
Please use this guide here step by step to contact support if you need further assistance.