I added Fallback fonts to all my TMP assets, and it’s worked great so far, being able to use Japanese and Chienese without any issues.
However, when using a drop down, when I try to add Japanese or Chinese to the Label, or the dropdown list content, all I get are squares, like I did before I added fallback fonts.
Is this a known issue or am I doing something wrong? literally just adding my font as I would to any label in my game. But the TMP SubMeshUI is not created as it is for other components.
Try making the font size smaller, I had a similar problem with regular Dropdowns where I replaced the labels with a TextMeshPro one, and these were not rendered if the font size was to large. Making the size of the item itself (in the hierarchy under DropDown/Template/Viewport/Content) bigger might also help.
I totally missed the fact that you are using version 1.3.0 and not the newer version with dynamic support.
Testing right now with version 1.3.0 with some fallback to see if the characters from the fallback get picked up correctly.
Update
Just tested in Unity 2018.4 with version 1.3.0 and 1.4.1 and it worked as expected.
For testing I simply created two new font assets. The primary with the ASCII set and the 2nd with a few Japanese characters. I assigned the fallback to the primary and then assigned this primary to both the label and template item label child. I then modified the Options on the drop down to use Japanese characters and everything rendered correctly.
I also tested removing the assigned fallback and got the squares and then re-assigning it, made those Japanese characters re-appear.
If none of the above points to anything that might be different in your case, please provide me a repro project and I will be more than happy to take a look to see if I can figure out why you are getting the missing glyphs.
The square is the missing glyph character which indicates the requested character and glyph is missing from the font asset.
It is possible those missing characters and glyphs are present in the font file but missing from your font asset itself.
I would suggest creating a dynamic font asset using this same font to see if those requested characters will show up.
Let me know the outcome and if the characters and glyphs still do not show up, please provide me with a link to the font file and list of missing characters and I can verify if they are present or not in this font file.