I'm not sure how relevant this is, but I'm sure it's not good.
Whenever I boot up I get an indexer error message as in the following screenshot;
It's the little box on the right.
As I'm typing this I'm installing six updates that were available, but the screen keeps changing from normal mode to safe mode and back again!!
It's also re-arranged all my desktop icons.
Any thoughts & sorry to keep troubling you.