Pages and Numbers have generic app icon in Dock I have a MacBook Pro 13" Unibody Early 2011  running macOS 10.13.6 (the latest it will support).
I wanted to replace the HDD with a 256GB SSD so I did a fresh install to the SSD in an enclosure then ran Migration Assistant.

As far as I can see everything is working OK, but there are couple of anomalies .
The Dock icons for Pages 8.1 and Numbers 6.1 seem to be some generic app icon.

I deleted the Dock entries and ran from Launchpad, but the icons remain.
In Finder the icons in Applications look OK although not in Launchpad.

I deleted  com.apple.dock.plist and ran the command  killall -KILL Dock

How can I restore the correct icons?
1)  In a Finder window Go to Applications.

2)  Locate the application's icon and do a Get Info.

3)  In the top left corner of the Get Info window the correct non-generic application icon should be displayed.

4)  Select that icon using the mouse.

5)  Do an Edit->Copy on the icon in the top left corner of the window.

6)  Do an Edit->Paste on the icon in the top left corner of the window.

7)  You may have to provide an administrator password.