Mojave Shepherd

I have had this problem for a couple of weeks now on both the LL viewer and Firestorm. Both viewers are the latest updates and FS was a clean install. SL is running on a '09 iMac, 2/8 GHZ, i7, 8 GB RAM, ATI Radeon. Profile window opens, displays for about two seconds then goes black. Very annoying. Any updates and/or suggestions are most welcome.

I have just purchased a 1024 parcel adjacent to my larger one. I have joined parcels in the past but now receive the message: "Not enough leased parcels in selection to join" What am I doing wrong?