Camera Raw Freezes When Trying to Access the Masking Tool Icon

Hi,

Several times now my camera raw app totally locks up when I click on the Masking Tool (the round brush circle icon).  The basic tab page works fine.  The minute I click on the Masking Tool, the pop up appears over my photo "Important Masking Changes" - picture of the cute little fox.  From that point it completely locks up, I have to go to Task Manager and have it stopped.  I'm working on all the lastest versions, including CR V.15.5.  How can I avoid getting the pop up ad?