Nagios Support Forum

My company licensed Nagios Pro in 2014, which included Nagios Core 3.5.0 and which we have never upgraded.
We wish to identify our options for an upgrade to the current Nagios core without purchasing the corporate Nagios XI 4.1 which is not within our budget.
The CCM we have installed appears to be v. 3.0.3 and we assume this also should be upgraded concurrently.
Any guidance on the proper versioned packages to install would be appreciated.

Unfortunately in this case the support we can offer is going to be limited to the versions you have installed currently. You are of course welcome to attempt an upgrade, or to spin up a new server and transfer over the configs, but without upgrading we can't officially support mixed versions like this.