Information Technology Training

SharePoint error
Cannot share a subfolder with an external user
Error: ResponseStatusNotOK (Entra B2B)
Guests invitations not allowed for your company

Azure AD - External Identities - External collaboration settings – Guest invite settings - does not fix the issue.

The subfolder ended up with a separate permission set from the main folder and over time, that permission set became inconsistent, which caused:

1. Users with access to the main folder not having access to the subfolder
2. Owners not having full control as expected
3. Errors when trying to share the folder

To prevent this,

1. Prefer sharing via groups where possible (instead of individual users)
2. Avoid repeatedly resharing the same subfolder with different individuals over time
3. If a folder starts behaving oddly (access errors, sharing failures), it’s usually a sign the permissions need to be reset