"Sorry, we're having trouble opening this item" is a generic Outlook error that appears when the application cannot access an email, attachment, calendar entry, or contact. The cause varies, but most are fixed without reinstalling Outlook.
Part 1. Clear Outlook's Temporary File Cache
The most common cause — Outlook caches attachments and items in a temp folder that can become corrupted:
- Close Outlook completely
- Press
Win + R→ type%temp%→ Enter - Look for a folder named
Outlook Tempor similar (search forOLK) - Delete all files in this folder
- Reopen Outlook and try again
Exact path via Registry (Outlook 2016/2019/365):
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Security\OutlookSecureTempFolder
💡 Tip: If you can't find the Outlook temp folder manually, search the registry key above for the exact path. Different Outlook versions use different temp folder locations — the registry key always points to the correct one for your installation.
⚠️ Important: Do not delete the Outlook temp folder itself — only delete the files inside it. The folder is referenced by Outlook's registry settings, and deleting the folder can cause Outlook to fail opening attachments entirely until the registry path is recreated.
| Error Cause | Fix | Expected Result |
|---|---|---|
| Corrupted temp cache | Delete files in OLK temp folder | Immediate — works after restart |
| Add-in conflict | Disable all add-ins, re-enable one by one | Works after identifying culprit |
| Corrupted OST file | Rename .ost → .ost.bak, reopen Outlook | Outlook rebuilds OST from server |
| Permission issue | Run Outlook as Administrator | Works if it's a permissions conflict |
| Outdated Outlook | Install latest updates | Fixes known bugs in older builds |
Part 2. Disable Outlook Add-ins
Conflicting add-ins cause many item-opening errors:
- Open Outlook → File → Options → Add-Ins
- At the bottom, select COM Add-ins from the dropdown → Go
- Uncheck all add-ins → click OK
- Restart Outlook and test
- Re-enable add-ins one at a time to identify the culprit
💡 Tip: Start Outlook in Safe Mode to bypass all add-ins without disabling them manually: press
Win + R→ typeoutlook.exe /safe→ Enter. If items open normally in Safe Mode, an add-in is the cause — then identify which one by re-enabling them one at a time.
Part 3. Rebuild the OST File
For persistent errors across multiple items:
- Close Outlook
- Control Panel → Mail → Email Accounts → Data Files
- Note the OST file path
- Navigate to it in File Explorer
- Rename
.ostto.ost.bak - Reopen Outlook — creates fresh OST and re-downloads from server
Part 4. Run Outlook as Administrator
Some item access failures are permission-related:
- Close Outlook
- Right-click the Outlook shortcut → Run as administrator
- Test if items open correctly
If this fixes it: the issue is a permissions conflict — check antivirus exclusions for the Outlook temp folder and PST/OST file locations.
| Outlook Item Type | Common Error Cause | Best Fix |
|---|---|---|
| Email attachment | Corrupted temp cache | Clear OLK temp folder |
| Calendar item | OST sync corruption | Rebuild OST file |
| Contact card | Add-in interference | Disable add-ins |
| Meeting invite | Permission conflict | Run as administrator |
| Shared mailbox item | Access rights issue | Verify mailbox permissions |
💡 Tip: After fixing the error, check if your antivirus is scanning the Outlook temp folder aggressively. Antivirus real-time scanning of temp files can prevent Outlook from writing attachment cache files, causing this error to recur after seemingly working fixes.
🗣️ r/techsupport user: "Got this error every time I tried to open email attachments. Cleared the Outlook temp folder and it fixed immediately. The temp folder had thousands of cached files from years of use."
🗣️ r/MSOffice tip: "If clearing temp files doesn't fix it, disable add-ins next. Third-party add-ins (PDF converters, CRM plugins) are frequent culprits for item-opening errors. Disable all, then re-enable one by one."
FAQ
What causes "sorry we're having trouble opening this item" in Outlook? Most commonly: corrupted attachment temp cache, add-in conflict, corrupted OST/PST file, or a file permission issue with Outlook's data directories.
Does this error mean my email is lost? Usually no — the email or item exists but Outlook has trouble rendering it. Clearing the temp cache or rebuilding the OST typically restores access without any data loss.
Why does this error appear for calendar items specifically? Calendar item errors often indicate a corrupted OST sync — the calendar entry on the server and local copy have diverged. Rebuilding the OST typically fixes calendar-specific versions of this error.
Can this error affect all emails at once? If all emails show this error, the PST or OST file is likely corrupted. Run ScanPST (for PST files) or rebuild the OST. If Outlook opens but shows this on every item, that's usually an OST corruption issue.