uninstaller / maintenance tool package manager and update do nothing

I'm trying to build an installer for my project and use the uninstaller to install updates. However, the update and package manager features don't work; nothing happens when I press the button. That is, there must be an update available, otherwise it just says 'no updates available', but when there is, next just does nothing.

And, when that happened, the 'remove' feature also doesn't work anymore. I have to close and start the program again to make that work.

I also tried making an installer without any javascript, which didn't help.

I also tried version 1.4. The only thing I was able to achieve with that, is that instead of doing nothing, it actually hung, needed a forced shutdown.