We have the same version, so I couldn't answer you for the version of your play.
On the other hand, for "Then how do I make a file developed on a more recent version (e.g. 2014) readable on my 2011 version."
The answer is: it's impossible!
You can trick the creator of the file to create it in STEP (but you lose your design tree). You can also redraw it if you're lucky enough to have a quote plan
And that's about it I think
The other possibility is to have an understanding leader who agrees to buy the 2015 version (or still be under contract. But if you're on 2011 I have a doubt ^^)
well, I'm going to drop this folder, I'm stuck with my version, well not quite I can switch to the 2012 version, but no more, because more means that I also have to change my PC for a story of 32 to 64 bits (or the other way around) according to Cadware.
So I'm waiting for more fruitful times because I'm the boss, and I'm doing with my means
@benoit, weird when I double click on capotlargap203 it doesn't ask me anything, directly it puts it on me in 2014. because usually I have a window that opens for the old versions of the file and asks me in which version I want to use it
Indeed, these files were saved in SW2014. For the 1st the original version is SW2011 then SW2014. For the 2nd, the initial version is older, SW2007 and then SW2014.
See attached image for the long hood. This information was extracted via "VersionHistory" from myCADtools.