This has floated around a bit over the years. You install Acumatica on a local instance, and you include RabbitMQ. Installation goes ok, or so it seems. However, when you try to access your local site, you get that dreaded message that RabbitMQ failed to load. Or maybe after some updates on your system, it stops working. What can you do? Well, the simple “fix” is to comment it out in web.config, but there’s a catch!
I was helping a colleague today with business events, and RabbitMQ being commented out (because it failed to load, and we took the easy route of web.config months ago) resulted in an error that MSMQ was not installed. Sure enough, we don’t enable it as a feature on our local machines. RabbitMQ was running as a service but failing with error when trying to access the website. In this case, we uninstalled ERL and RabbitMQ, rebooted, deleted the last of the ERL(something) folder in Program Files. Then using the extracted files of the installer package from the same build on builds.acumatica.com, we reinstalled ERL OTP and then RabbitMQ. Honestly, to my surprise, it worked.
Why disable RabbitMQ in web.config? If running locally, you may never run into a problem. If it makes you happy and works for you, just disable it in web.config.
<!-- <add key="QueueType" value="RabbitMQ" /> -->However, certain aspects of Acumatica such as Business Events requires it (or MSMQ) to function. In that case, uninstall, cleanup, and reinstall. See if that fixes RabbitMQ. Unfortunately, no guarantees it will work. For one, you have to be sure you grab the right version from one of the Acumatica installers and not just the latest and greatest from the internet. If all else fails, you always have the option of disabling RabbitMQ and enabling the Windows feature for Microsoft Message Queuing and hope that helps.
Good luck! :)