Oh, yeah, objects being updated more than once could cause all sorts of issues.

Maybe play around with the SEPARATE_BIAS value: https://api.haxeflixel.com/flixel/FlxObject.html#SEPARATE_BIAS

Instead of var foo(get_foo, set_foo):Bar;, you now have to use var foo(get, set):Bar;. This was a change in Haxe 4.

Are you sure the error is on that line / do you have a bigger excerpt?

What does the file path to the project look like, does it contain any strange special characters perhaps? I think people have also had issues with creating projects in system32 accidentally (default location of cmd.exe unfortunately).

This was fixed in Flixel 4.7.0, so simply running haxelib update flixel should do the trick.

It looks like you simply don't have the HaxeFlixel / FlashDevelop project template installed (it's not built-in). I think you can install it via AppMan.

In case somebody else runs into this and stumbles over this thread, somebody on GitHub seems to have found a fix: https://github.com/HaxeFlixel/flixel-tools/issues/72#issuecomment-565801794

You're not doing anything wrong, the Lime extension simply doesn't support HashLink debugging yet. You don't have to debug to build + run though, use the "lime test" task for that.

The PS4, XB1, and PSVita backends are now deprecated:

https://www.fortressofdoors.com/setting-boundaries-open-source-gamedev-on-consoles/