toolbar - no symbols?

[#1]

I created a toolbar and wondered why all the symbols are just "?":

In the Add In editor the symbols showed up correctly:

I almost gave up till I found the problem:
The ":" in the Add-in ID.
The symbols are saved in the folder 
C:\Users\...\AppData\Roaming\SAS\JMP\Addins\AddinName
To get a correct folder name, JMP replaces the ":" with a "-" ... but seems to have problems with it.
Replacing the ":" with another character solved the issue

JMP 16.2

[#2]

nice tip, thanks

[#3]

Sent a note to the dev team. Thanks!