Thank you for your post.
When you type, does the cursor move? If so, then it could be the text color is set for white. There are two possibilities... In Browse Mode, select the field, pull down the Format menu and change the Font color to Black. The other is to go into Layout Mode, select the field, pull down the Format menu and change the Font color to Black.
If the cursor doesn't move, then make sure the field is not a calculation field. If it is not a calculation field, make sure you have access privileges set correctly so that you are able to Edit the field.
If you are still running into difficulty, please let me know.
Thanks. I changed something in my startup and rebooted and now works fine.