Hi Md.administrator,
Based on the error messages, if you have
turn on Microsoft teams for your organization recently, please wait patiently for a few hours for the changes to take effects, then ask the affected users try again.
Moreover, for users to access Microsoft Teams, you need to check and make sure you have assigned the
Microsoft Teams licenses to your users.
If you confirm all above settings are correctly but the users still cannot access Microsoft Teams, to help you better, we need to collect following information for analysis:
1. Please login to Microsoft Teams admin center >
Org-wide settings > Teams upgrade and send us a screenshoot of this page.
2. Please send us a screenshoot of one affected user's licenses.
3. Please send us a screenshoot of the error message.
Best regards,
Jennifer