Thank you for sharing some information regarding your concern today, Benjamin.
I'll share a reason and give you a workaround for the error you've received. A possible reason why this occurs on your end is due to having an old version of Microsoft Outlook. Our engineers have determined the root of the cause of this issue and already working on a fix. In the meantime, please let your colleague log into Microsoft Outlook Web on a browser and have them accept the invite there.
As a workaround, you can:
- Instead of using a desktop, let them accept the invite using Outlook online or any webmail client.
- Let them accept the invite from a mobile device.
- Tell your colleague to update the Outlook desktop to the newest version.
Also, I recommend contacting our support team so they can add you to the list of affected users and receive updates once it's fixed. You can follow these steps to contact our customer care team:
- Sign in to your QuickBooks Online company.
- Click Help (?).
- Select the Search tab to get started:
- Search: Search the QuickBooks Online knowledge base directly, or select Contact us and choose a way to connect with us:
- Start a chat with a support expert.
- Get a callback from the next available expert.
In addition, you can refer to this article if you need help in adding and managing users in QuickBooks Online: Add and manage users in QuickBooks Online.
If you want to know what to do if the invited users didn't receive your email invitation, you can visit this article for further guidance: What to do if invited users did not receive your email invitation in QuickBooks Online.
For any concerns and questions regarding QuickBooks, feel free to leave a comment. We're just one click away. Keep safe.