Apparent thread hang

[adgray1]

Creating a bug per original post:

So for the last few hours, I've been dealing with a NovaUI lock-up, without explanation. The lock-up is happening on the NovaUI independent update thread.

Here's the screenshot of the NovaUI code that is the culprit (where Unity3D is locked up):

Surely this is at least in part a NovaUI bug -- the system shouldn't just Lock-up without some form of explanation... or error beforehand, etc. There appears to be no form infinite recursion, or anything. But the CPU of Unity3D stays high while it's locked up. The only Unity3D thread with anything meaningful in the stack trace points to Nova UI.

I'd not be so bothered by this, since it's a new product, if I could see the source code, and help to debug it. But we are locked out, and now I'm wasting yet another night on NovaUI for no good reason.

[adgray1]

If you're on Nova version 1.2.0 or 1.1.9, one thing worth trying is updating to the latest version of Nova. There's only one Nova hang we've observed, and it was introduced in 1.1.9 and later fixed in 1.2.1. If you're on 1.2.1 or later, then this is likely a new (to us) issue.

[najak3d]

That might be it. I resolved this issue myself, after many dozens of Unity restarts.

I'm creating custom versions of Dropdown, which behaves like a Multi-menu selection-DropDown. I just kept testing my code with break points, looking for bad logic and applying small fixes, and retesting -- until the Lockup stopped.

I ended up doing so many varied types of things, that I don't know what fixed it in the end.

I really wanted to see source code during this process, as it may have saved me many hours.

I was using Unity 2022.2, from a few months ago. Right now, I'm uninstalling all of my versions and starting over, since the Unity hub itself had gotten borked (wouldn't upgrade to the next version of the hub). I didn't realize that uninstalling the Hub would uninstall ALL versions of Unity I had installed -- but that appears to be the case.... as a result, I don't know the specific versions of anything right now.

You can close this issue, since it's now working.

What I would have preferred to do was debug the issue with real source code, and then simply tell you what I did to improve your source code, or give you more details about the issue.

[najak3d]

I was using Nova 1.2.2 when it was just mysteriously locking up - as shown in my screenshot.

If I had source code, I would have GLADLY debugged this for you better, and maybe even suggested a fix. This would have helped me, you, and everyone else. That's why we need source code -- it just makes this a better world for everyone. :)

[najak3d]

When I encounter a bug like this - I realize there are usually two bugs.
#1 - one with NovaUI - the fact that it was "mysterious" without explanation or errors -- just locks up. This should never happen (or very rarely). And so I FIRST spend time to debug that issue...

#2 - once I(we) fix NovaUI to "report the error" (make it obvious to the developer what has gone wrong, with hints on how to fix) -- THEN I fix the other error in my code.

BTW, I was the original author of Visual3D.NET (and co-founder of Realmware), which went belly up in 2010, after Unity3D took all of our customers, leaving us no revenue. We were a full .NET-based 3D game engine, and offered Source Code licenses, and never had any backlash from doing so.

[najak3d]

RIGHT NOW - Facing this Lockup again. I wrote about 100 lines of UI code to alter how I construct my multi-select dropdown.... and rather than seeing an error, malfunction, etc --- NovaUI is again simply Locking up. This means that until I resolve this error (via trial-and-error), I'm going to be restarting Unity3D many times, once for each failed attempt (shot-in-the-dark style guessing).

I'm not going to share the details here of the code/setup, because I'm guessing I'll have it fixed by guessing-method within a couple of hours.

[najak3d]

Here is my "DropdownSubItem" prefab -- which is used recursively. In this graph, "Sub2OptionsList" contains the ListView, where the prefab for that ListView IS this same DropdownSubItem prefab. I'm not sure how else I'm supposed to do this, other than what I've done.

[najak3d]

My theory is this (which could be confirmed if I have source code...) --- is that I'm adding items into the ListView... and then when it creates the next ListView, it's cloning the "CURRENT" instance of fDropdownSubitem, which now has One Item in the ListView...,

The more I think through it -- the more this seems to be the root cause of my mayhem.

I need for the NovaUI logic to use the "unchanged prefab from resources", and never copy the instance that I'm USING (and changing).

[najak3d]

Another full night, spent on NovaUI, getting very little done. :(

I'm only hanging in here now with NovaUI, because I have faith that you'll be supplying source code soon, because it's really "the right and best thing to do"... I hope you agree, quickly. So that I can start being more productive.

[adgray1]

Thanks for the additional details and screenshots!

Based on the info here, does answer 2 from this thread resolve one or more of the issues you're observing?

Relevant quote:

2. In your FolderButton prefab, don't do this:

If you try to use the root of the prefab as a list item directly, when the ListView goes to duplicate it, it will end up duplicating the scene object instead of the prefab asset. This is just Unity serialization behavior, not a Nova thing, but the result will be undesired either way. The workaround for this is to create a Prefab Variant of FolderButton and assign FolderButton Variant to the ListView items in FolderButton, and then assign FolderButton to the ListView items in FolderButton Variant. If you make that change, then at every level the ListViews will be instantiating prefab assets instead of scene objects.

[najak3d]

I came to that conclusion myself before bed -- but was too tired to try it.

NOTE--- I was NOT using the object from the hierarchy as the Prefab, but rather the Prefab from the Project.... but there seems to be a nuance in Unity where when you try to do this, it short-circuits it to thinking you want the Root Object of the Prefab as the Prefab (since they are sorta "the same"). So it wasn't allowing me to do what I was trying to do.

Creating a 2nd "DropdownItem2" prefab which then points back to "DropDownItem" prefab -- works like a charm though.