I noticed that on me and my friends characters, none of us could sign up for Adidas, Puma, or Cobra sponsorships via myCareer due to constant crashing immediately after signing the sponsorship.

After many many testings and crashes later, I discovered that if you create a new character and do the career on that one, it let me sign up for all 3.

Now I will explain that my first playstyle was Technician. I'm not sure if it's related to which archetype you go, but it might. My second was powerhouse. I haven't had any of my friends test out on 2nd characters, but I believe it may be working. If not, comment and I can update the guide.