Where have my text options gone?

I was working from a reference file and was able to see the text details but for some reason they have now disappeared. This essentially means that I cannot change or view any aspects of the text.

How do I get them back?

See screen shot, left is reference file (no text options), right is working file (text options available)

In the screenshot on the left, the text style is applied to the object, on the right, no style is applied to the text.

Please see the Help Center article: