Why does this happen? (runtime error message: "No group 4")

[ABG]

This is wonderful!

You have stumbled upon the very same text replacement bug as another user who tried to use '$' in a text replacement operation.

Replace certain letters by $ symbol

In order to correctly display the letter s in a special font within a linguistic app, I need to replace all the letters s by the well-known $ symbol. Unfortunately, I always get an error message. The app works fine though when I change the $ symbol into any other letter or symbol. Is there a useful workaround for this problem? Thank you in advance. [blocks] [Runtime_Error] [Screen]

Two people in a day, after no reports for years.

DO not allow any '$' in your text replacement fragments.
You have one in that global list.