Tools-Options-"Edit" tab-Edit directly in cell

make sure this options is checked.

"SunkInSeattle" wrote:

When clicking into any given cell, a user has two options:

1. Clicking once will allow user to replace all cell material when followed
by typing
2. Clicking twice will allow user to run around inside the cell to edit
where necessary

Question - Suddenly I no longer have option #2. I can edit a cell via
toolbar, but am no longer able to edit cells by double-clicking into any
cells. I have tried everything (copy/paste, new files, restart) with no luck.
What did I do?