sed error: "parentheses not balanced" - But they are!
 

I have a list of words, and some of them have parentheses around them like:
" (( hello )) "

I'm trying to remove them with sed, but it says that "parentheses not balanced"

The sed command is:
sed "s/([ ]?\)\)[ ]?)|([ ]?\(\([ ]?)/ /"

... and the exact error is:
sed: 1: "s/([ ]?\)\)[ ]?)|([ ]?\ ...": RE error: parentheses not balanced

You can see I escape all of the literal parentheses. What am I doing wrong?

Thanks.

try:
sed "s/((\([^)]*\)))/\1/g"

Ok, that works. Thanks..