Hi Sam Holdman,
Good day.
Thank you for posting to the Microsoft Community. We are glad to assist.
May I know if you are getting an error message when you try to create a new category in New Outlook for Windows or with classic Outlook for Winodws?
This issue could be caused by several factors, such as a software glitch, a problem with your account settings, or a corrupted Outlook profile. Here are some possible solutions you can try:
For New Outlook for Windows:
- Go to account settings from New Outlook for windows and in categories, try to edit and create new and check.
- If still same issue: try to repair New Outlook for windows
For classic Outlook for Windows:
- Check if the categories feature is enabled in your account settings. To do this, go to the Home tab and select Categorize in the Tags group. Select All Categories. In the Color Categories dialog box, make sure the categories you want to use are checked. If not, check them and select OK.
- Try repairing your Outlook installation. To do this, go to Control Panel > Programs and Features, select Microsoft Office, and click Change. Then select Repair and follow the prompts.
- If the issue persists, try creating a another new Outlook profile. (do not delete old profile)
- Press Windows logo + R to open Run Command.
- At Run command type Control Panel and click OK.
- If Control Panel View is in Category, click the drop-down and select Small icons.
- On the Small icons Control Panel view, click Mail (Microsoft Outlook xxx (xx bits)).
- Choose Show Profiles > Add.
- In the Profile Name box, type a name for the new profile, and then choose OK.
- Follow the instructions to add your email account to the new profile.
Should you have any questions or concerns please do not hesitate to contact me. Look forward to hearing from you
Best Regards
Microsoft Community Moderator