Lightroom CC 2015: Crashing on (Win 10)

Last night I uploaded a lot of photos with LR2015.13 (win 10 platform).  Seemed fine. TodayI tried synching to my ipad but it wouldn't transfer photos. I clicked on my name on the upper left to start synch and now LR crashes everytime I try to start it. I updated to 2015.14 but still the same. No other changes (but the computer did restart last night so wondering if a windows update is responsible). I tried using LR Classic CC but it tells me there is a duplicate catalog so I'm afraid to click on anything there (I'd be happy to use Classic CC if I can solve the catalog issue).  Please advise. Thanks