As of today, i am unable to enter or edit excel formulas which use a comma to separate the terms within the formula. When i display a formula previously created with the comma, it appears as a blank. This is a new issue. When i called Microsoft supports chat line, the lady helping me in India tried with her excel and had exactly the same problem. I tried updating, repairing my office installation, uninstalling and re-installing it and nothing worked. Please help.