Not sure if you got a solution to this.
I have encountered the same issue. It looks like it was caused when I upgraded my OS from Server 2008R2 to 2012 R2. I tried to recreate my Certificates without luck.
I logged a call with Support and after trying a number of things I have decided that as this is only a Test Repository I am going to recreate it. There does not appear to be a way to fix that Secrets Key. The Support Techie did say that he had put in a request to enable us to fix the Secret Key via QMC but considering that that Secret key helps to encrypt data it could be pretty difficult to change the secrets key.
The only real solution seems to be to restore to a last known good backup of the Repository or recreate the repository.
I'm facing the same problem upgrading a multinode site from 3.0.1 to 3.1.3 version.
the problem involve only rim node.
attached the rim node log with the error.
How can I fix it ?
IT'S URGENT !!!
Many thanks in advance.
If I remember correctly in the attached document contains information on how to decrypt the connection.
I tried to apply the resolution suggested in the following article https://qliksupport.force.com/QS_CaseWizardKnowledgeArticle?Id=ka5D00000004Nu7IAE
but the error still persist !!!
where can I find in QMC the ID listed in the log file generating the error ?