What to do if I created by mistake a user with a profile but without access to any organization?
Open role related to the created user
Go to Org Access tab
Click on New Record and in combo select their parent organization (if there is more than one, repeat this step).
Go to User Assignment tab
Find your previously created user and click on User/Contact. This will take you to the User Maintenance.
Go to Org Access tab and add their parent organization.
Do not select access to *, add access to their real organization in order to relate user - organization.