Converting Regular Expressions to Browser UI

System

Greetings everyone.

Perhaps someone can tell me how to convert this expression from the java UI to the browser UI:

validation-regex="(?s)^.{0,8000}$"

I have been getting an error when trying to save a DCR originally created with the java UI later opened with the browser UI. When I re-save it, I get a regular expression error. I have read some articles talking about the differences between the reg exp engines, but I am not sure how to make the change.