Can't find plugin "AlteryxRPluginEngine.dll"

[MeanLeanDean]

After updating to v2021.2.1 yesterday, I started getting this error: 

Error: TS Forecast Factory (233): Tool #20: Can't find plugin "AlteryxRPluginEngine.dll"

I tried uninstalling and reinstalling the Alteryx Intelligence Suite (2021.2) to no avail.

What changed?  And how do I fix this?

[twyunting]

Where can I download "RInstaller_2021.3.3.exe"? Because my current version is "AlteryxInstallx64_2021.3.3.63061.exe".