Error message when switching browser from Retina Display to "Normal" Display

Hi,

I get this error when I switch my browser from a Retina Display (iMac 5K) to my Dell (U2717D 2560x1440.

[code]Unhandled NilObjectException
Message:

Stack:
RuntimeRaiseException
RaiseNilObjectException
WebCanvas._SendCmdToPage%%os
WebGraphics._Update%b%ob
WebCanvas._RefreshInternal%%obb
WebCanvas._SessionScaleFactorChanged%%o
WebSession._ExecuteEvent%%osA1v&b
WebSession._HandleEvent%%oso<_HTTPServer.HTTPRequestContext>
WebSession._HandleRequest%i8%oso<_HTTPServer.HTTPRequestContext>
WebApplication._HandleHTTPRequest%%oo<_HTTPServer.HTTPRequestContext>
_HTTPServer.HTTPRequestThread.Event_Run%%o<_HTTPServer.HTTPRequestThread>
RuntimeStackCheck
RuntimeTextFromOldString
crt_at_quick_exit
BaseThreadInitThunk
RtlUserThreadStart[/code]

It seems to happen only on Mac. I don’t get the error on my virtual machine.

HiDPI webpictures are not the right size on Mac but they are showing perfectly on Windows.

Is it a bug?