Individual printer interface loads oddly/fails to load.
On occasion when switching from one printer to another, the interface will fail to load properly, instead showing all of the buttons/variables with no data.
Here's a screenshot to better explain:

Comments
What I see is that angular did not replace the placeholders, so there will be some error in the script/html preventing this. Open debug tools and check debug console. I think you will see some error messages that cause it.