Last night I managed to update to Sierra. Now there is a problem with the OS X speed. I read that there are Spotlight and iPhotos indexing stuff in the background.
However, the main CPU usage comes from ReportCrash. I looked through the logs, but the new console messages appear quickly (about 1000 per minute). I've spoted the keychain, spotlight, security and some other keywords there.
I searched the net to find a solution, that required reseting the Keychain to default and then rebooting. Doesn't help though.
Most of the lines in the Crash Logs mean nothing to me and there are no useful advice that I was able to find.
As I understand, there is no sense in waiting, as the Spotlight indexing keeps crashing and will never be completed.
UPD: I am not able to login to iCloud with my Apple ID either. It might be part of a problem.
UPD2: According to the system processes, Spotlight, Dropbox and some other apps are constantly starting up and crashing.
UPD3: tried EtreCheck. Chose the "Apps are crashing" option. The diagnostics started. Then the EtreCheck crashed as well.
Here is the part of the log: Link
It's been two days since I started this Sierra update and the problems keep appearing. I'll appreciate any help.