This means that you tried to score a dataset using a model. The model uses as an input feature a column called "Variable# 2" but your dataset (or the output of the preparation on your dataset) does not contain this feature. Thus, you cannot apply your model on this dataset.
This means that you seem to be have been using to train your model features that are not available at scoring time.
If it is "normal" that you don't have this variable in your dataset to score whereas you had it in your training dataset, then you should retrain the model without using this feature (by rejecting it), since you can't use it anyway.