Text Mesh pro font sometimes doesn't render on iOS - 2018.2.1/2

I've recently updated Unity to 2018.2.1 and also tried 2018.2.2.

Both are giving me a bug where rarely (about 1/20 launches of the app on iOS) one of my fonts (always the same one) doesn't render at all.

Inlined icons render correctly and are rendering in the correct position.

I've looked in the debug log in xCode and there are no errors.

If I restart the app, the font renders fine. I've never seen this on Android or in Editor or in 2017 versions of Unity.

 

I'm pretty sure i'm only using TextMeshPro objects.

I'm not using canvases in my game. So this is not the problem. It's not a sorting issue as this font is not visible in any of the UI screens it's rendered where as the inline icons are.

And as I said when you restart the app it's fine.

If the font does not render on app boot then it never renders at all.

Edit:

When updating unity I upgraded from the plugin version of TextMeshPro to the built in version of TextMeshPro could this be related?

 

I'm guessing the render queue should never be -1?



Edit: Although all my font materials are -1. Does that just mean use shader default?

 

It's hard to check because it's so intermittent... I'll dedicate tomorrow to finding better reproduction steps.

I do have a custom shader (edited from the standard TextMeshPro Mobile shader) to add a couple effects. Maybe there's something in the latest version it doesn't like... sometimes...

 

Scaling doesn't make sense in my case either as it's missing in all UI that has this font and a lot (if not all) of those screens and UI elements never scale.

 

I haven't seen the bug again after regenerating the font. But it's only been a day. I'll keep an eye out and let you know if it's still around.

 

Here are some Unity Performance reporting issues that are new and could be related to the issue I am seeing.

 

The fallback font i use for foreign currency symbols had an invalid shader. Could that create those exceptions? In editor all I get is pink quads but no errors when using those symbols.

Edit:
I can't get the fallback font to work. I just get these warnings.
"Character with ASCII value of 8383 was not found in the Font Asset Glyph Table. It was replaced by a space."

Edit 2:
Removing the fallback font and then assigning it again fixed those warnings. This is really building my confidence.

 

Is this something you can make more robust? Exceptions are bad especially on Android as Unity basically abandons the rest of that frame and keeps running and then you're left in an unknown state.

 

The shader was missing after the conversion from the previous Text Mesh Pro to Unity 2018.2.x

I think there needs to be some safety checks at least in editor. Also why would I have not got these exceptions in editor? I've only see them on Android.

I can't seem to find the source code to see exactly where and why it would have broken. Has that source been removed in the latest version? It's hard for me to understand if it's fixed if all I know is the function name of where it broke.

 

No, all my text uses this shader so I'd expect to see a lot more issues than what I'm seeing. I think it was just because it wasn't assigned after the upgrade.

I think we also might be dealing with two problems here, one where sometimes the font doesn't display (Only seen it on iOS still, but not since rebuilding the font), and the other which is the exceptions on Android. The reason I think they are separate is because they are related to different fonts and one ( the exceptions ) will only be an issue when a currency other than $'s is used, hence why I didn't catch it in my own testing. I'll have to add those other symbols into a debug menu or something so i can more easily test they work in future.

Ok thanks, I'll take a look tomorrow.


I've rebuilt all my fonts, double checked all the shaders and started another partial roll-out on Android. I'll soon see in performance reporting if the issue is fixed or not. I'll let you know.

 

It looks like it's fixed as I'm only getting the usual 'libunity.so' crash bugs in performance reporting now.

This means your upgrade tool failed somewhere I guess. Maybe when in combination with custom shaders it fails somewhere?

Just to reiterate, What I did to fix the issues was

- Re-generate all the fonts in the game.
- Un-connect (set to none) and reconnect the fallback fonts.
- Double check all the shaders were assigned to all the font materials (custom shaders all lost their connections).
- Went through TextMeshPro settings and reset them all to what I had them before the update (default font had changed).

 

That's kinda annoyingly difficult to do. Internet in Australia sucks real bad so I'd have to download the whole project and upload the whole project which is a few gig... it'd take a couple days...

Yay Australia!