Variable name with special character causes all stacks to be hidden and program will not work

[Mr-Dave2]

Expected Behavior

Program stacks should be visible and the program should execute as it does on Scratch 2.0

Please describe what should happen

Variable names, even ones with Unicode characters, should have no effect on displaying program stacks or how the program executes.

Actual Behavior

Stacks and the variable are not visible and the program will not work.

Steps to Reproduce

I don't know where this character came from. I have tried other Unicode characters and I have not found another one that causes any problems. Credit to @shu279 for creating variable names that start with �. I was playing "Cat's Step Adventure -Part1-" https://scratch.mit.edu/projects/194603038 by shu279 and wanted to try it on Scratch 3.0 but it would not work and none of the stacks could be seen.

I did a cut-n-paste to create a variable with the special-character name in a new Scratch 2.0 project (https://scratch.mit.edu/projects/217845144/) and then created a small stack that used that variable. When loaded into Scratch 3.0, the stack is not visible and the program will not work.

I also tried a cut-n-paste into vim and the character showed up as a control-H. Vim does not support Unicode so this probably does not mean anything.

Operating System and Browser

Windows 7 (64 bit), Chrome 65.0.3325.181

[Mr-Dave2]

I found another program that will not run or display its stacks and it’s apparently also because of characters used in a name (of a list this time). (Actually, it does something; it will play a sound for about a second but there is no motion).

The program is https://scratch.mit.edu/projects/215321405/ and for Scratch 3.0 (https://llk.github.io/scratch-gui/develop/#215321405). I remixed the program and the only change I made was to delete the list named “>> Highscores <<”. After saving the project I could load it into Scratch 3.0 (https://llk.github.io/scratch-gui/develop/#218249134) and it would run with stacks now visible. (The sound still stops after one second but that is a different issue: “Deleting clones while playing notes causes music extension to stop working #1018”.

[Mr-Dave2]

More people have reported this as the likely problem with their projects.

All projects that use the PTE projects to draw text (https://scratch.mit.edu/projects/172111618/).
This user mentions the problem in this post https://scratch.mit.edu/discuss/topic/299791/?page=254#post-3190127 and another mentions it here: https://scratch.mit.edu/discuss/topic/299791/?page=254#post-3190125

I have three more test cases:
This project where a list has a "&" in its name 2.0 & 3.0
This project where a variable starts with "<" 2.0 & 3.0
and this project where a broadcast has a "&" in its name: 2.0 & 3.0

Windows 7, Google Chrome Version 68.0.3440.75 (Official Build) (64-bit) and Firefox 61.0.1.