# Outlook Error: Could not read calendar



## tigerdg (Jan 4, 2011)

After a recent MS office update, I began getting an error upon opening MS Outlook. There's a yellow exclamation point in a small popup that reads, "Could not read the calendar." It also appears if I switch to another Outlook function (like the calendar, with which, incidentally, there is no problem) and then back to mail. I have to click "OK" in order to proceed. I've checked to make sure I have all current updates both for Office and Windows (10). I've also rebooted several times, did an Office repair (both short and long), but the problem persists. I've also checked the MS forums, and while the problem is known, no one has posted a solution. Some have suggested it is an inability to communicate with the iCloud calendar, but I do not use that and have no idea how to connect to it.










Using:
Dell XPS 8930 computer
Windows 10 Professional, v 20H2, OS build 19042.867
Microsoft Office 365

Thanks for any help with this. I don't know if it's relevant, but this problem appeared about the same time as I began having difficulty sending e-mail from this account.


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## Corday (Mar 3, 2010)

Have you tried removing the Office update? If you try a System Restore, you'll lose all updates since the restore time/date you've chosen and will need to reinstall what you need.


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## tigerdg (Jan 4, 2011)

Corday said:


> Have you tried removing the Office update? If you try a System Restore, you'll lose all updates since the restore time/date you've chosen and will need to reinstall what you need.


"System Restore" does not appear to be an option under my version of Windows 10, but I was able to uninstall the last two Windows updates I did around the time the problem appeared (4/6). I removed them one at a time, but neither was effective. I then reinstalled them, and the problem persists. I really first noticed it right after I did a MS Office 365 update (I was working on another e-mail problem I thought an update might solve), but I don't see a way to uninstall Office updates. Do you know?

Thanks for your help.


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## smithcharlee (Mar 5, 2021)

Try Microsoft's CheckCal tool. The Calendar Checking Tool for Outlook (CalCheck) is a program that checks the Microsoft Outlook Calendar problems very easily. As per my experience.


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## tigerdg (Jan 4, 2011)

smithcharlee said:


> Try Microsoft's CheckCal tool. The Calendar Checking Tool for Outlook (CalCheck) is a program that checks the Microsoft Outlook Calendar problems very easily. As per my experience.


I found this tool, but it is for use only with Outlook installations that are on an exchange server, and I am not. Thanks though. Any other ideas?


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## Corday (Mar 3, 2010)

You do have System Restore: Use System Restore unless you purposely shut it off.


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## tigerdg (Jan 4, 2011)

Corday said:


> You do have System Restore: Use System Restore unless you purposely shut it off.


Yes, I found it. However, this is a relatively new computer and I have never created a restore point, so I don't have one to go back to. Good idea, though.


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## Corday (Mar 3, 2010)

Check your settings. Things like Windows Updates can automatically create a point even if you don't create one manually. Turn On System Restore Point Setting and scroll to:
*How to enable System Restore on Windows 10*


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## tigerdg (Jan 4, 2011)

Corday said:


> Check your settings. Things like Windows Updates can automatically create a point even if you don't create one manually. Turn On System Restore Point Setting and scroll to:
> *How to enable System Restore on Windows 10*


Okay, I did that, but I still don't have any restore points to return to except the one I created today. Evidently, it is turned off by default, which I did not know. I've turned it on now, but I still don't see a way to access any restore points that might have been created after an update.


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## Corday (Mar 3, 2010)

I was hoping it was on. Glad it is now for the future. Since you've already tried repairing MS Office let's go for a reinstall. Even though there will be an option to save your data, back it up any way. Download and install or reinstall Microsoft 365 or Office 2019 on a PC or Mac


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## tigerdg (Jan 4, 2011)

Corday said:


> I was hoping it was on. Glad it is now for the future. Since you've already tried repairing MS Office let's go for a reinstall. Even though there will be an option to save your data, back it up any way. Download and install or reinstall Microsoft 365 or Office 2019 on a PC or Mac


Hi, and thanks for sticking with me and this rather intractable problem. While your suggestion is a good one, I am going to hold off on this step for two reasons: 1) I've done both a local repair and an online repair going through Control Panel/Programs and Features/Microsoft 365/Change/Repair with no success; and 2) I have been made aware that this issue is common among Outlook users and began with update KB5000842 and that Microsoft is working on it. (I should note here that I have uninstalled said update and still have the problem.) It should (stressing the word 'should' here) be fixed in a future update to be released (I hope) soon. Also, following your procedure, even if I didn't lose my data (and yes, I would do a backup on my own), I would lose all my customizations and I hate that. If push comes to shove, I will try this. Stay tuned, I will post any developements here!


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## tigerdg (Jan 4, 2011)

UPDATE: Someone on another forum asked if turning off the calendar in the To-Do bar solves the problem. I have found that it DOES, but only partially. If I have the calendar showing in the To-Do bar, the message appears upon opening Outlook, upon opening the calendar the first time ONLY, and every time I go back to mail. If I remove the calendar from the To-Do bar, the message does NOT appear upon opening, but does appear the first time opening the calendar. It does not appear at all after that. All very curious.


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## tigerdg (Jan 4, 2011)

Microsoft has finally fixed this. It was not through an update, but somehow they did something so that one only had to restart one's computer and open Outlook and the problem was fixed. Seems pretty solid that it was a Microsoft Office update that caused the issue.


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## smithcharlee (Mar 5, 2021)

It is not a wise idea to 'Use System Restore' or 'Reset this PC'. Sometimes, just restarting the PC fix the problem


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