training sub microflow

I am doing the sub microflow training in this link  : I am in 8.22 to be exact. in the step   To create a sub-microflow, follow these steps: Select all the activities from the create variable to the last merge.   But when I select I error saying : "Selection cannot be extracted into a new microflow,because events cannot be extracted" .          Why is this happening and how to fix. Additional information: I tried deleting all elements that uses the parameter and I was able to extract. But will only extract the microflow without the validation.    
1 answers

You have all of the activities selected in the screen shot. Only select the validation part of the microflow. Right after the last merge. I believe that this happens because there are multiple possible endpoints to the submicroflow that you are trying to create.