Unexpected escaped character '<' in regular expression.
1. Outside [ ]
[ ] { } \ / | . ? + *
2. Inside [ ]
[ ] \ / - ^
it's not always needed to escape "-" inside brackets, but it's safer ( think of e.g. [a-c-e] which is the same as [abc\-e]). ^ has to be escaped only if it's at the beginning of the set.
Greetings, Wolfgang