Yes.. I have the same issue on one Mac. It initially installed, but after uninstalling for a clean install i receive the same message re Mounting the boxcryptor disk. The logs show:
6/10/2015 9:46:43.510 AM CoreServicesUIAgent: error -1 while removing quarantine data on path /Applications/Boxcryptor.app/Contents/Frameworks/BoxcryptorFoundation.framework/Headers
6/10/2015 9:46:43.715 AM Boxcryptor: Failed to connect (helpMenuItem) outlet from (BCStatusItemController) to (NSMenuItem): missing setter or instance variable
6/10/2015 9:46:43.930 AM Boxcryptor: [HockeySDK] -[BITHockeyManager startManager]/201 INFO: Starting HockeyManager
I uninstalled it because it was hammering the CPU and thought a clean install may remediate.. On my second Mac however its reproducing the same behaviour re an ongoing high CPU load. I have disabled it on this machine. So I have currently have no local access to my Boxcryptor data. No AV installed on either PC. Thank you for addressing this as a high priority.