T4 System Plugin update error

Hello, I tried to upgrade the T4 system plugin from 2.3.7 to the latest one 3.3.7

I hit UPDATE and i receive this

When I go to check for updates nothing has happened

Please help, not sure I can solv this issue: This extension does not provide a checksum for validation of the integrity of the downloaded file.

Thanks, Indrit

IDesign With our products, you should use JA Extension manager component to update. It can't be updated via Joomla update channel.