This article describes how to fix Cannot open your default Email folders. The information store could not be opened error when opening Outlook profile. In most cases, it is usually caused by:

.ost file corruption

  1. Remove old profiles you do not use from under Control Panel > Mail > Show profiles:
  2. Re-create an .ost file. Read the Knowledge Base article on How To Create, Compact, Repair Or Delete Offline Folders (How To Rebuild OST file) for more information.
  3. If the issue persists, create a new profile from scratch:

If the problem continues, it is most likely caused by Outlook client running in compatibility mode.

Outlook is running in compatibility mode

To switch off the compatibility mode in 64-bit operating system:

  1. Navigate to C:\Program Files (x86)\Microsoft Office\Office XX\Outlook.exe
  2. Right-click on Outlook.exe and navigate to Properties > Compatibility tab
  3. Uncheck the Run this program in compatibility mode box, click Apply and OK.