I love the Forums software. I have used it for decades. The price is a bargain.
But please let me be so bold as to say that the number of bugs introduced with each new version is almost unacceptable. Look at all the poor operators of boards who have substantial issues with the latest version who post in this forum with crisis situations that have brought down their income stream, caused great consternation among their users (who are community members often very invested in the forums through their time or money), or both.
Does development of the Forum include the running of a formal series of tests during the development process, using Selenium or a similar product? I'm talking about a suite of hundreds of tests that would check almost all aspects of the functionality of the Forums, which potentially are affected by software changes.
Could the software include a diagnostic tool for operators that would flag potential vulnerabilities in their plug-ins or in their themes, which they could run before an upgrade? Not just a check of PHP version, etc., but something that would assess the customer's particular set of installed hooks and themes. It couldn't check for every potential problem, of course, but it could flag the characteristics of the hooks or themes that would be likely to cause problems with future upgrades, by testing them against some kind of "interface" standards that the Forum hook/theme developers should follow and that the Invision developers would follow. Maybe this is being done to a degree already, but if so then I submit it needs to be amped up in a major way.
Again, I love this product.