Problems connecting to a database.

Please I need help with the following problem.

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The server principal "Server Name" is not able to access the database "Database Name" under the current security context.(Monitor Tool)

What configuration I'm missing to solve this problem?

You need to check in Configuration Tool if the OutSystems DB Users have the correct permissions.
Do the "Test Connection" action on each one (Admin, Runtime, Log and State). If you get an error running the test connection, click on "Grant Permissions" to try fixing the problem.

The problem must be with the Runtime user, but check them all.
Thanks for the quick reply. I had to grant access to the Runtime account in SQL Server.