I had an issue with the validator and came across this post on the old forums:
It wasn’t really resolved but I did need to figure it out.
I’m on 2.8.1-pl
Turns out I do NOT need to surround the regex with any delimiter. So don’t add /…/ or %…% to the pattern.
And I DID need to double-backslash any time it was used.
My pattern was for a text box and only allowing a ##,##,## type pattern. It has to start with a number, and not end in a comma, and not allow multiple commas in a row. The pattern was exactly this:
If I add % or / around it, it fails. If I have single backslash, it fails.
Just in case anybody searches for this type of issue.