Why is Conditional logic showing "Missing field error"

Also, I noticed that there are a lot of conditions on your form with the missing field error, please fix them or the other conditions may not work as expected. 

 the above blurb was from one of the techs, have these gone missing because I changed the background theme? they were there on the previous form.....

The reason the conditional logic is showing the error is because the fields that needs to be hidden or shown are missing hence the condition is not complete.

You may need to re-check at the conditions and the missing fields and how you want these fields to be displayed then add them fields to the condition.

Below is guide on how to setup conditions.

https://www.jotform.com/help/57-Smart-Forms-Using-Conditional-Logic

Kindly do let us know if you need further assistance.