Why am I always getting an error when finishing an extraction of new fields using the Field Extractor utility in Splunk 6.2?

[StijnJans]

In version 6.2 adding new fields via the wizard always results in this error:
In handler 'props-extract': Argument 'value' contains invalid character. e.g. for regex : ^(?:[^\|\n]*\|){4}\s+(?P[^ ]+)[^\]\n]*\]\s+\[(?P[^\]]+)

Anyone any idea what is causing this? Tnx!

[martin_mueller]

There appears to be a unicode escape character (U+001B) in your regex...?