You should never copy RB files from one version into another.
There are supporting files and subfolders, which you have probably missed.
The weird "ifplugins" folder is NOT where ANY Plugins go, either !
You have the latest Mirror [v6.0] RBZ downloaded.
RBZ files must be 'installed' !
Use the Extensions [-Manager in v2017] > Install Extension... button and choose that RBZ to install it semi-automatically.
Alternatively IF you have the SketchUcation Toolset you can use its ExtensionStore³ to Auto-Install any chosen PluginStore tool, skipping download step etc...
PS: Mirror works fine in v2017 - although it still needs re-signing to work in all Loading Polices...
Statistics: Posted by TIG — Tue Nov 22, 2016 8:35 pm