The session setup from computer 'TESTBOARD-PC' failed because the security database does not contain a trust account 'TESTBOARD-PC$' referenced by the specified computer.
If this is the first occurrence of this event for the specified computer and account, this may be a transient issue that doesn't require any action at this time. If this is a Read-Only Domain Controller and 'TESTBOARD-PC$' is a legitimate machine account for the computer 'TESTBOARD-PC' then 'TESTBOARD-PC' should be marked cacheable for this location if appropriate or otherwise ensure connectivity to a domain controller capable of servicing the request (for example a writable domain controller). Otherwise, the following steps may be taken to resolve this problem:
If 'TESTBOARD-PC$' is a legitimate machine account for the computer 'TESTBOARD-PC', then 'TESTBOARD-PC' should be rejoined to the domain.
If 'TESTBOARD-PC$' is a legitimate interdomain trust account, then the trust should be recreated.
Otherwise, assuming that 'TESTBOARD-PC$' is not a legitimate account, the following action should be taken on 'TESTBOARD-PC':
If 'TESTBOARD-PC' is a Domain Controller, then the trust associated with 'TESTBOARD-PC$' should be deleted.
If 'TESTBOARD-PC' is not a Domain Controller, it should be disjoined from the domain.