I can see that the error in displaying the parentheses occurs in the dialog as well. I don't know enough about how things are encoded to offer much help. It is possible that the internal error detected might have something to to with the problem, and contacting Wolfram Research about it might be helpful.

If restarting Mathematica while holding down the option and shift keys does not 'fix' the problem, then the cause and resolution are beyond my experience. sorry.

Just a guess, but your language preferences may be messed up. There is a setting in Mathematica preferences to handle this.

From your time notation in the menu bar, you appear to be using a language other than English for your system. I might double check that as well.

You could try restarting Mathematica with the option and shift keys down to reset it to a known state.