What’s going on with Outlook Classic? Are there known issues?
Asked by
CuriousOtter27
I've been hearing from various users that they've been having inconsistent problems with Outlook Classic under M365, particularly receiving the error message *"Information Store could not be opened."* Even after trying to create a new profile, they still can't connect to the server. Sometimes, the issue resolves after a day without any changes made. Has anyone else experienced this, and if so, do you have a solution?
Answers
I’ve had similar issues a couple of times lately. Switching to the new Outlook for a day and then going back to Classic seems to be a temporary fix. In fact, one user loved the new version and decided to stick with it!
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I'm experiencing the same issues on my side! I’m based on the US East coast and it seems to happen frequently.
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Microsoft has had a rough patch lately with various server errors and issues. There have been 404 and 500 errors coming up on admin centers, plus it looks like they've changed some URLs again. It’s not just Outlook that’s affected.
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We've dealt with similar issues. It turned out that Microsoft changed their CDN for Outlook updates, and our firewall settings weren’t updated accordingly. Once we fixed the firewall, Outlook started working again. It might be worth checking your firewall settings!
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I haven’t faced this directly, but have you checked for any updates to Outlook? Sometimes they sneak new versions in without notice, which can mess with the classic version. If that's the case, it may be grabbing the mailbox and disrupting the classic service.
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My Outlook tends to hang for several seconds without an explanation and then it resumes. It makes me suspicious that Microsoft is trying to phase out Classic to push everyone to the new version.
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I encountered this problem as well yesterday. I fiddled with it for about an hour until it started working again, almost like it fixed itself.
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UpdateSeeker33: Do you have any links to the new URLs they’re using?