It should be Every time not everything.
Every time? I get it too, and it is infuriating, but for me it's not every time.
Which LR6 do you have? Is it a perpetual licence Lr6 or do you have it via CC?
I looked at the order again and it's LR6 not LR6 CC. It's not every time
because if you start it once and wait a minute 'retry' works otherwise the
other option sometimes work.
perpetual licence Lr6 downloaded from Adobe.
Found the problem. If your HD spin down you will get the Windows pop-up
"Server Busy". If you prevent you Hard Drive(s) from going into the idle
mode (spin down) you will not have the prompt when you start LR6.
I have the problem in Lightroom CC with the Server Busy error. Preventing the Hard Drive(s) from spinning down does not fix it.
Neither does the step of renaming SL Cache and SL Folder -- in fact, so far nothing fixes it.
Still waiting on Adobe to puzzle this out...............