Please, which version of Captivate do you use?
Could you tell which mode of capture you use: Demonstration, Training or Assessment? I suspect you want to have typing in text during capturing be transformed to Text Entry Boxes? This works only in Training/Assessment mode, check the Preferences, Recording, Modes (see screenshot, this is for Training mode). FYI: this transformation works fine in Captivate 5 but I had problems with it in Captivate 4 before where it was not always done.
Be sure to type in text in the text fields while capturing. It will be replaced by a Text Entry Box with an associated variable and validation.
Sorry for the lack of information. I'm using Captivate 5 and I have tried the Assessment, Training and custom recording modes without any consistent success. Sometimes it works, sometimes it doesn't.
First I created a Custom template where I checked the Text Entry Box checkbox, including the Failure Captions and Limited Attemps checkboxes. I tried to record off of that template and it didn't work. Then I opened a new project, created my preferences again (using Assessment this time), recorded, and it didn't capture it.
I just opened a new project, clicked record, recorded in the Assessment mode and only changed the preferences to include text captions and highlight boxes, and it worked. I don't get it!
As usual difficult to find the cause. Up till now I did not have issues with this conversion of typing text to TEB's in Training/Assessment mode, and then it is not easy to look for an answer. I'll start with the usual questions: do you start Captivate as an administrator? Did you install the patch released in December (I never heard from another user about this issue however). And what do you get if it is not working: do you have a Typing object instead of a TEB as would be the case if you were capturing in Demonstration mode?