.*any character (except for line terminators), repeated any number of times
\[the literal [ (9110 / 1338 / 5B16)
ERR]the literal text ERR] (case sensitive) \h*any horizontal whitespace character, repeated any number of times
Non-Capturing Group(?:\R.*){2} {2}repeats the group contents below exactly 2 times:
\Ra newline sequence
.*any character (except for line terminators), repeated any number of times
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string