Outlook for Windows

1. Basic Fixes
 Restart Outlook
Exit completely (Task Manager ends Outlook.exe) and reopen it
 Repair Office
Control Panel > Programs and Features > select Microsoft 365
Click “Change” > “Quick Fix” > “Repair”
Restart your computer when done
2. Mail synchronization issues
Update Inbox manually
Press F9 to force synchronization
 Rebuild Outlook data file
Close Outlook
Delete/rename the following files (rebuild automatically):
%localappdata%\Microsoft\Outlook\*.ost  
Re-login to your account
3. Stuck/crashed interface
Safe Mode Startup
Press Win + R and type:
outlook.exe /safe  
Test if it works (if it works then it may be a plugin conflict)
Disable hardware acceleration
File > Options > Advanced
Check “Disable hardware graphics acceleration”
Restart Outlook
4. Calendar/Meeting Issues
Reset Calendar View
Switch to the Calendar module
Right click Calendar > “View Settings” > “Reset View”
Check time zone settings
File > Options > Calendar
Ensure that the time zone is consistent with the system
5. Ultimate Solution
Create a new Outlook profile
Control Panel > Mail > Show Profiles
Click “Add” to create a new configuration
Set as default and restart Outlook
 Completely reinstall Office
Use the official uninstall tool
Reinstall from office.com