Following an update in April 2023, users who have not logged into OpenGround for a period of time may find that they are no longer able to log into their accounts.
This is because a security update has been applied, ensuring that users who have not logged into OpenGround for 90 days, will have their accounts deactivated. Further reasoning on this has been detailed in the blog article which can be found here;
Security Improvements : User Account Deactivation Policies
To enable a user who has been automatically deactivated, login to OpenGround as an Administrator, select the user from the grid and then select Edit User. From here, simply change the dropdown for Active back to Yes from No. The user will then be able to log back into OpenGround again. If the user does not login again for a further 90 days, the process will need to be repeated.