Error: “You are a member of the max. number of teams allowed. You must leave some teams to continue”
You will receive this error on creating a new Team, While the error description is misleading you do not need to leave existing teams to create a new one.
If you have allowed tenant your users to create teams and they are not the global administrator then they have a limit of creating only 250 Teams as per the Microsoft Limits and specification of Microsoft Teams and this limit is exempt only for global administrator.
How to solve You are a member of the max. number of teams allowed Error in Teams
Here’s how you can solve this issues, You do not need to assign a global administrator for the users. Thankfully Microsoft released four new admin roles one of which is Team service administrator, which has the ability to create and manage office 365 Groups.
Assigning Team administrator role for the effected user will remove the error. Assigning this permission give some other privileges to the user, so make sure to double check the “Team Service Administrator” permission carefully before assigning to user.
Login to Office 365 Admin portal
You need to assign Team administrator role to the effected user So, in order to do this login to your Office 365 admin portal and assign the Teams Administrator role to the user.