Blogs
on November 9, 2025
Are you having trouble starting Outlook or receiving "Cannot start Microsoft Outlook. Cannot open the Outlook window" error messages? We can fix the problem for you, or you can use the troubleshooting steps we're providing below to help resolve these startup issues. Your Outlook profile holds all your account settings and data configurations.
Currently, you can't use Outlook on Windows to edit calendars that are shared with your Outlook.com account, even if you've reconnected your Outlook.com account to Outlook. We're working to make it possible to edit shared calendars in Outlook 2016 for Windows. If you are having issues sending email, this might be due to validation issues with your Microsoft Account. We are aware that some users may not be able to receive email from Gmail accounts.
Add-ins are extensions that you can install to enhance Outlook’s functionality and unlock additional features, like CRM integration. But these add-ins can sometimes result in compatibility issues, especially if they’re not up-to-date or poorly coded. A conflicting add-in might cause Outlook to freeze, crash, or not open at all.
Moreover, this utility allows you to repair multiple PST files simultaneously without needing any modifications. Whether you're dealing with ANSI or Unicode PST files, the tool can effectively recover them, ensuring data integrity and recovery. Stellar Repair for Outlook Technician repairs corrupt PST files and recovers complete mailbox data.
Stellar Exchange Server Backup is an excellent software to take backup of full Exchange database or selected mailboxes. It minimizes Exchange downtime by restoring all mailboxes directly, without interrupting Exchange server services. You have important things to do in your Yahoo account, so let's get you back in! After you regain access to your account, consider switching to 2-Step Verification to avoid sign-in issues entirely. It's free, more secure and will require a verification code in addition to your password. If you still can’t recover your account, you can create a new Google Account.
Yes, you can often fix Outlook without reinstalling Office. A damaged or corrupted Outlook user profile is a common reason for "Outlook won’t open" errors. Creating a fresh profile can provide a clean slate for Outlook to start. Outlook stores all your email messages, meetings and events, contacts, and tasks in data files.
Hitting spam traps—those sneaky addresses designed to catch spammers—or being listed on a blocklist can seriously damage your standing. Putting weeks of planning and Outlook troubleshooting guide effort into an email campaign…only to have it fail to deliver. When we asked email marketers their key priorities for our annual State of Email Survey, monitoring their deliverability rates hit the top five.
Verify your internet connection and confirm there are no outages in your area that could be affecting your connectivity. Customers using the contact support buttons at the foot of the support pages, or the "email us" links in support Virtual Agent, are unable to open the Help Pane. Some customers may not be able to see their Profile, Account or Sign Out options when selecting their picture on the top toolbar. Some users may not be able to empty their Deleted Items folder. Check that you have not accidentally blocked the Gmail domain when blocking one Gmail user.
Stellar Repair for Outlook is a professional tool to repair large and severely corrupt PST files and restores data with 100% precision. It supports recovery from Outlook 2019, 2016, and earlier versions. Stellar Mailbox Extractor for Exchange Backup repairs and extracts data from corrupt Exchange BKF & VHDX backup files. This software also exports offline mailboxes to live Exchange Server.
If this profile becomes corrupted, it might fail to load or cause Outlook to crash upon opening. Such corruption could result from improper shutdowns, software conflicts, or corrupted files within the profile. Microsoft regulatory releases new updates for Outlook and Windows (or macOS).
The best part is that you are spoiled for choice because some are quick to implement while others are time-consuming. This section introduces solutions that you can use when Outlook 2016 or Outlook 2013 is not opening. If none of the above steps work, the issue may be more complex or related to server-side problems that only Microsoft can resolve. Find solutions to common problems or get help from a support agent.
There are also notes about legacy per-user auth being an issue, however we had two accounts left in per-user auth but none with the issue. If you think that it is patch related, roll back the patch and see if that fixes it for the end users. If it’s an RDS server and the cache is also on the server, if the server crashes, reboots abruptly, is full, there are many reasons. Instead of removing the profile, remove the OST file and let it recreate. Find solutions to common problems or get help from a support agent.