We continue to evaluate the RoboHelp 2019. We currently use RoboHelp 2017 and occasionally RH 2011 (don't ask).
We will need to work on certain projects in RoboHelp 2017 even if we upgrade. Can our older projects continue in RoboHelp 2017?
I emailed the Adobe accounts development manager with this question and he said "Adobe Licensing Policy does not allow you to access the older versions."
I don't know if I agree. I sense that if I open the old project in RoboHelp 2019, yes, I cannot revert back to the older version. But I do believe that multiple versions can coexist as long as I do not open a legacy project in RH2019.
Can anyone let me know what their experience has been after upgrading?
There are two aspects to what is allowed, technical and legal.
On the technical level, you can install as many versions as you like as long as they are supported by the operating system. That doesn't mean you can open a project from a later version in an earlier version, just that you can open projects in their version.
On the legal side, no one on this forum other than Adobe staff can give you a definitive answer and my response should not be construed as setting out what you can or cannot do legally.You will need to read the licences with each version in the light of what you purchased.
With that qualification, it has always been my understanding with most software licences that if you purchase a full licence each time, then you can run all of those, subject to any technical issues. However, if you only purchase an upgrade, it is usually the case that you can only use the upgraded version. That is a general matter and may not be the case with Adobe's licence.