Why "The calculation for this question is invalid" error?

[Teresa_Blader]

A client is setting up calculations in Survey123, and in the past this isn't a problem... but today every time a new calculation is set up, the message "the calculation for this question is invalid" pop up with a warning. Even though the work flow is the same and not complicated at all.... it's literally just spitting out the answer of a previously answered question. Doesn't matter which question we select for the calculation.

Ones that were there in the survey before, upon opening do not have an error, until a new calculation is set up, then it pop up with errors. 🤔 

[Richard_Purkis]

@Teresa_Blader I am unable to recreate the issue in a test survey just referencing a previous number question. Are you able to recreate the issue in a new survey?

[Teresa_Blader]

Oddly enough, no I do not get the error when I make a new survey. Also oddly enough that these are new surveys the client is making. Ones that were already published pre-error show the error if you go in and reset the calculation, but they don't show an error when opened. There's a series of about 20 surveys all populating dashboards that are doing this. The questions that are set up with the calculations to reference the previous value are also set as "do not submit". But alas, I cannot recreate the error from a fresh survey. 😕