If you use a different system font to those 3 you mention, the crash doesn't happen?

Those are the only system fonts that I have tried for now.

Could you try more system fonts to see if it is happening with ALL system fonts? Thanks

I have tried some other fonts but the problem remains.
I have extracted the Helvetica.ttc font from /System/Library/Fonts/Core on the iPad 2 and imported it as a normal font inside the unity project.
I was able to use it this way on the iPad 2.
What could be my next step?

Could you please do the following things:

1. That the device with problems is an A1395, A1396 or A1397 (can check the number in the back of the iPad)
2. Attach a minimal unity project reproducing the issue (for example a single XAML with a textblock using a system font)
3. Verify the the minimal sample works in rest of iPads but crash on iPad2.

Thanks!

Yes, the iPad model is A1395. I will create a small project and submit it.
If it is possible can I know what is the problem :)?

I don't know what is going on because I am not able to reproduce it in the iPads we have here. I ordered an iPad2 for testing.

Here is the project.
I have tested it on the iPad 2 and the problem is still there.
I will just need to check that it works on the iPad Air.
I will let you know as soon as possible.

I Have uploaded the wrong Assests folder.
This should be the correct one.

Thanks, please, let me know when you verify it works in the iPad Air.

Sorry for the late reply but I could test this only today.
I can confirm that it works on the iPad Air.

Thanks for the feedback! I will keep you posted.

I already tested this on iPad2 and I am able to reproduce the issue. That's a good start... :)