Hi VickileeOAC,
Thanks for reaching us in community.
For this problem, you may open a web browser and go to https://teams.microsoft.com/ to see if you can update your team picture successfully.
If you have ever installed Team app in your smart phone, you may also try the following steps to change picture of your team;
- Find your team, and click "...",
- Select Edit team > Change picture,
- Then you can upload picture from your phone library.
If you still cannot change the picture, would you like to share a scrennshot of the error page your failed to perform this action? So that we can have a better analysis on your situation.
Best,
Shawn