I usually get something like this if I deleted an object but the object was used in an instruction within my program.
I am not positive but I think you will see an object's slot filled in with "None" if the object was removed. I believe deleted variables and parameters can also leave this type of problem behind.
Ivacy VPN comes with a slew of features that are designed to improve your online experience. There are numerous reasons why you should download Ivacy VPN for Windows on your computer.