Symptoms

Error when accessing designer/runtime

"Server Error in '/Identity/STS/Windows' Application.
/ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length]"
 

Diagnoses

The specific error in this case states that the full error message cannot be shown due to it's length. We recieved a debug assembly to surface the error from the K2 Labs team, however, as this is a production environment, we were unable to use it as it would impact availability.

We guessed that we were encountering an error involving one of the certificates, as one node in the cluster would throw the error, and the other would not.

 

Resolution

We checked the certificate store on both machines, and found that the K2 self signed certificate was missing it's private key on the non-working node. We deleted the certificate from the non-working server, exported the certificate from the working server with the private key, and imported it on the non-working server. Once the certificate was imported, the issue was resolved.