SystemLink 19.5 RabbitMQ Unable to Connect

[CFEARING01]

We are having an issue with our SystemLink Server using SystemLink 19.5. When logging into the SystemLink Web Interface, the only icon that shows up is Jupyter

Then when opening the NI SystemLink Server Configuration, a RabbitMQ issue is detected

We have restarted the server and repaired the Rabbit packages via NIPM and neither helped. I have not encountered this issue before and unsure how to resolve

[JoshuaP]

If you open up the Windows Service Manager do you see the RabbitMQ service and is it running?  Is this a new server that you are setting up or an existing server that just stopped working?

[CFEARING01]

This is an existing Server that stopped working. If I open Services I do see RabbitMQ listed with a status of "Running". I see it as well in Task Manager under erlsrv.exe

[JoshuaP]

Do you know of anything that could have changed recently on the server that may have caused the issue (changed the hostname of the server, installed a new firewall/virus scanner)?

An invalid RabbitMQ certificate can also cause the services to fail to connect to the broker.  Can you right-click on the rabbitmq-server.cer file under C:\ProgramData\National Instruments\Skyline\Certificates\rabbitmq-server and Open it to verify the Valid from range is appropriate.  We have things in place to handle it, but wanted to double check.

Also, may be quicker to setup a conference call to walk through everything.

[CFEARING01]

Not that I am aware of, but I also don't have purview to everything that may have happened to it. If any of this info helps, feel free to respond, meanwhile I will work on coordinating a conference call

I verified the certificate:

We did find this, however, 

I ran the diagnostic tool and found that there is an issue with authentication ("TCP connection succeeded but Erlang distribution failed"). It appears this could be a cookie mismatch. Googling RabbitMQ and this issue finds this that may be helpful

https://groups.google.com/forum/#!topic/rabbitmq-users/a6sqrAUX_Fg

[CFEARING01]

Resolved by Josh P and NI Team. If you encounter the same issue, contact NI. Would not recommend attempting to resolve on your own.