I have not been able to complete but 1 upgrades in Wendy's Workshop, and not because I haven't been able to complete tasks, but but cause of the limit on the number of cards you can hold, and then not being able to get the cards that I need to complete sets! The upgrade I am working on currently needs 4 batteries! Any time I open a set of cards I get everything BUT batteries! Which forces me to use cards to make oil instead of being able to hold onto them. I also currently need 1 level (yellow card) and I only have one yellow task left to complete but none of the tasks before that gave me a level. Either the number of cards you can hold onto needs to be increased, or there needs to be more variety in the cards that are given, or more variety in the cards needed for tasks, or ALL THREE!