"Completed task" marker has gone... :-(
I am using the latest Windows client and I have noticed, that the "completed task" marker has gone. It used to show when I clicked on a task to complete it. On the web client it is still visible. Could you please restore this marker in the Windows client? I'm very accustomed to it. :-)
Please right-click on the TD icon in the notifications area (system tray) and use the "Logout" option and then log back in and see if it fixes this issue. If not, uninstall the app and install this version: https://d2dq6e731uoz0t.cloudfront.net/5023a6d6c92501bdfb0e00969703a767/as/Todoist_for_Windows.exe and let us know if the issue persists.
Uff! It's OK now. :-) The trick with "Logout" option helped.