Example: A common example of this is Country/State dynamic visibility. Based on the Country selected, the State field will show with dynamic values. So say that on the form, there are 50 values for the State field and there are also specific values under the visibility rules that are associated with the Country selection. It is likely that the values in the visibility rules do not match up with these 50 field values. If you select US and the dynamic values are the full State names, such as California, but the value in the State field is CA, the visibility rules will be attempting to display a value that does not exist.
The solution is to either change the visibility rules' values, or change the field values, so that the values match.