Glad to hear. It should be fixed in 3.1.1. I can't say for certain there isn't another path to the same error, but I certainly did track down at least one exact reason why this error occurs.
FYI, this was all a timing issue. During the initialization process, the software kicks off a patch download. When the active Data Store doesn't exist, it causes the warning dialog to show, which essentially "pauses" the initialization process. When the patch finishes downloading, it expects the Settings dialog to be initialized. Because the initialization is paused, the Settings dialog remains uninitialized, and boom we get an error. So conceivably anything that might slow down the initialization process could cause this to happen, so long as a patch is downloaded relatively quickly. It doesn't have to be that the active Data Store could not be found.