Making sure the right tool settings are loaded and recent firmware is loaded can prevent a variety of problems and often this will fix issues without doing any sort of diagnostics.
Open the ShopBot control software and type a UR command (or click on Utilities > Reset Default Settings values on the top menu bar). When asked to clear the system log, click Yes. Click Yes and OK to the next two boxes that pop up. A window should pop up asking to select a settings file for the tool. Click on the profile that matches the tool (PRS ShopBots folder for tools like the PRS Alpha, Standard, Desktop, and MAX. Settings for older ShopBots folder for PRT tools, BenchTop, and PR).

