With the 0.17.25 update the mod throws up an error noting a faulty upgrade recipe
(>PaA-power-armor-mk3-upgrade< Duplicate item ingredients, Proccessing Unit exists twice or more)

To fix this:
Go to the map: %appdata%\Factorio\mods\PowerAndArmor_1.17.34.zip\PowerAndArmor_1.17.34\prototypes
Open the file: recipe.Lua
go to row 92 (use Notepad++) and delete this row
Save the file and its fixed

Thank you. It worked perfectly.

=-) your welcome!

I have fixed the bug in the newest version, thank you for reporting