validation regex's not working in 5.5

System

I am trying to use simple validation regexes that I have cut from templates that were created for version 5, when I try them in 5.5, the dcr wont save unless I cut them out. Here's a sample.

<item name="whatever">
<text
required="f"
validation-regex="(?s)^.{0,90}$"
</item>