Scenario: SharePoint 2016 MinRole Farm with 2 Servers.
I tried starting Microsoft SharePoint Foundation Sandboxed Code Service in one and in both servers as I found this: Can't Activate Solution from Site Settings in SharePoint foundation 2010 and used the PS cmd:
$SA = Get-SPServiceInstance | Where {$_.Id -like “*GUID*”}
$SA.Provision()
This made that service start on the servers but shown as Not compliant in Central Administration>Services on Server. Anyway, by having this service running, it didn't make a difference and the Activate button kept been disabled for a new solution (template.wsp) I uploaded to the Solution Gallery.
Can you advise how to make the Activate button Enabled?