This document has not been formally reviewed for accuracy and is provided "as is" for your convenience.
In the Performance Center UI, a "Failed to connect to PC Service" error message is received when trying to run a scenario (which is not even reaching the initializing state). The Lab Management's "System Health Check" didn't show any problems. Environment was working the day before.
In the PC Server's LTLogger logs, we found the following error: "ERROR HP.PC.DAL.Impl.DbContextImpl - OpenConnection. System.Data.SqlClient.SqlException (0x80131904): Login failed. The login is from an untrusted domain and cannot be used with Windows authentication."
IUSR_METRO's password had expired.
Make sure the PC User account (IUSR_METRO/P3rfoRm@1nce by default) still exists in the Database machine and is part of the Administrator group.
Setting the password the same way as the PC User from the rest of the environment and made sure to check "Password never expires" so that it didn't happen again.