I have a couple of applications with a state unknown. I knew it was a credentials issue and setup an account that has local admin access. This account, as it's a test account has a very weak password as I wanted to see if it polled. I guessed we would have because all of the other 200 + applications polled correctly.
I tested it on one of the unknown applications and it polled successfully. I then wanted a more secure password (I generated one in keepass) pasted it onto the account, tested it on the server to ensure it wasn't too complex, then updated the account credentials on solarwinds.
I then wanted to see why the local admin account wasn't working (I guess because it's not a domain account) I updated the local admin password on solarwinds on this node, and tried again. No such luck.
I then noticed that the application was down (I guess it was because of the password change) I reverted to password change, then waited some time for the DC replication, tried again and still nothing.
Now it's back in a state of unknown and I am still not entirely sure why it worked fine and then stopped working. If anyone has any ideas then that would ne appreciated.