Dynamic value in text box doesnt not wotrk anymore

[imyconco]

Since the update in Nov/ Dec I cannot longe use this feature, which I have been using all along, why? how can I fix this, i need to use  this all the time! When ever I type something is not regognized and the Save button is greyed out:

 Many thanks for your help in advance!

[Greg_Deckler]

@imyconco I'm on the February version and I can get it to work. But, your "How would you calculate this value" needs to resolve to something.

[imyconco]

@Greg_Deckler I also have the February version and I sued to be able to add a field or metric in the "How would you calculate this value" box, but since December I cant. Could it be a particular setting that changed when I updated to the latest version? 

[Greg_Deckler]

@imyconco Not sure. I don't have pretty much any preview features installed on my system. So maybe try turning off all the preview features and trying again? Perhaps one of them is interfering with this. Here is when I try to add something that is not in my data model:

And here is when I type the name of something in my data model: