Forum Discussion
Installation option turn off preview features
"If you want to disable this preview as an administrator, set the following DWORD value to 0 in the registry: AllowV3Models in either HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Microsoft Power BI Desktop SSRS or HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Microsoft Power BI Desktop SSRS."
See:
Power BI Report Server January 2021 Feature Summary | Microsoft Power BI Blog | Microsoft Power BI
Memorable Member"If you want to disable this preview as an administrator, set the following DWORD value to 0 in the registry: AllowV3Models in either HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Microsoft Power BI Desktop SSRS or HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Microsoft Power BI Desktop SSRS."
See:
Power BI Report Server January 2021 Feature Summary | Microsoft Power BI Blog | Microsoft Power BI