When I tried to open Lightroom (LR5.6) today, I got the following error message:
Clicking OK closed the program but it did not solve the problem. Same message when I tried to open it. Re-booted computer (PC Windows 7) and tried again. Same problem.
Tried to "repair" Lightroom from installation files. Same problem.
Uninstalled Lightroom and re-installed. Same problem.