If a key on the keyboard is running a wrong action, e.g. it inserts the curly quote instead of the square bracket, you are facing a wrong assignment of the GN4 script to a key.
1.Find out the name of the key that is performing a wrong action as explained in Revealing VB.NET names of keys on the keyboard and make a note of the key name (let's call it 'wrong key').
2.Find out the name of the key that is supposed to perform the same action and make a note of the key name (let's call it 'wrong key').
3.Run Ted or Fred and then find out which script runs when you press the key that is performing a wrong action as explained in Find which GN4 script runs when you do something. Make a note of the script name.
4.Do one of the following:
•If the problem happens in text editing, search the file TED4_TABITEMS.XML for all occurences
Example
When you press the [ key, the curly quote is inserted and not the square bracket.
Now, that means that the KT revealed the name OemOpenBrackets in the first step, that the KT revealed the name Oemtilde in the second step, and that the Script editor revealed the name EditInsertCurlySingleQM in the third step.
This means you have to unassign the OemOpenBrackets from the EditInsertCurlySingleQM shortcut, and assign it to the Oemtilde.
Edit the configuration file as explained in Change an existing keyboard shortcut.