Previously I added it to my project and had to fix namespace errors - classes or enums with same names, right now it doesn't give me any error (I tried deleting and reimporting it several times).Are you getting any errors? My guess is that something is causing an error which is preventing the tasks from loading.
If you aren't getting any errors are you able to narrow down what is causing the issue? One way to do this would be to duplicate your project and slowly remove assets, or create a new project and slowly add assets.