I am running Windows 10 but the problem was happening before the upgrade so I don't think windows 10 is the problem
I googled the issue and tried the following suggestions:
Things I tried to fix the problem:
Method 1:-Set as default within outlook.
1. Open Outlook, Click on File < Options.
2. Under General, in Start up options group check the option Make Outlook the default program for E-mail, Contacts, and Calendar.
Did it and it did not correct the problem
Method 2:- Set as default from control panel.
1. Navigate to Control Panel< Programs< Default Programs< Set Default Programs
2. Select Outlook under Programs list and click on Set as default.
3. Click Ok.
Outlook is not there
1. Navigate to Control Panel< Programs< Default Programs< Set program access and computer defaults.
2. Click on the arrow mark pointing downward next to Custom to expand Custom option.
3. Under Choose a default email program, highlight Microsoft Outlook and click Ok.
Under choose a default email program
Use my current email program is the only choice and there is no Microsoft Outlook choice
2) I downloaded the Microsoft Fix-it button and ran it and it did not fix the problem
1. Click Start, and then click Run.
2. In the Open box, type regedit, and then press ENTER.
3. In Registry Editor, locate the following subkey in the registry:
4. Select the subkey, and then press DELETE.
5. Click Yes.
6. Quit Registry Editor.
7. Start Outlook.
8. For Outlook 2000 and Outlook 2002, click the Help menu, and then click Detect and Repair .
For Outlook 2007, click the Help menu, and then click Office Diagnostics .
For Office 2010, Click Start, click Control Panel, click Programs and Features, select Microsoft Office 2010 and then click the Change button. Next, click Repair, and then click Continue.
Did this but it rebuilt the key but I am still getting the error