:wink: Try them to open in OLDER versions of Eagl*
Eagl* old versions available in MCU fileman.
I dont think any standalone viewer is available for Eagle.
This happens if one of the E@gle versions is not an original one or yoursoftware version is smaller than the one you got your files from.
I guess it's a copy protection problem. My suggestions are eighter ask for a gerber printout or try to find a tool (I know it exists but I forgot the name) that can restore e@gle files from a cr@cked version so you can open them with a legal one.