I don't know if this "problem" is by design but it is causing great issues in collaboration.
I work with pople that have AutoCAD versions 2010, 2011, and 2012. We agreed that all our collaboration dwgs would be version 2010. When I change annotation scale in my drawing (having ANNOAUTOSCALE turned on) to update annotative objects to current scale, AutoCAD does this to xref drawings also, but aditionally upgrades xref dwg file version to 2013. My colleagues then can't open their own dwg files since they are upgraded to 2013 version.
Problem:
AutoCAD 2014 upgrading externally referenced drawing file version when automatically adding annotation scale to objects in main drawing.
When ANNOAUTOSCALE is turned on, AutoCAD automatically adds annotation scales for existing annotative objects, including annotative objects in xrefs. This means that AutoCAD must modify externally referenced drawings to add annotation scales to annotative objects. AutoCAD then modifies external DWG to latest supported version - 2013.
Is there an option to set AutoCAD to leave current version of externally referenced DWGs?
"...but aditionally upgrades xref dwg file version to 2013."
Are you the 2013/14 user? The only 2013/14 user?
If so, does setting your File Save As setting (Options, Open and Save tab) to 2010 version dwg not resolve the problem?
I can't think of any other option but to make it a habit to re-open and re-save the xrefs back down to 2010 version (until you can get the other users upgraded so you're all on the same version).
As a work-around, you can use TrueView to batch-downsave large numbers of DWG files. Not ideal, but can save some time.
As far as any settings which affect this - I think you may be SOL. This operates in a similar fashion to DWTs and AEC content always being the "native" format of the current AutoCAD version.
Picking your battles is important, and getting everybody into the same release is a good one to invest in. It prevents a *lot* of stress.
It's pretty bad that you're blaming the user for this problem, when it is clearly an AutoCAD issue. I'm having the same problem. I'm running 2014, while the rest of the team is running 2010. We are going to upgrade everyone soon enough, but until that happens, it would be nice if this wasn't an issue. Here's my experience. I'm only opening files in read-only mode for review. If there are other AutoCAD files xreffed in, there's a good chance that when the 2010 users attempt to open that file, they are unable to, and are told it was created in a newer version. The strangest part of this bug, however, is that the file itself doesn't appear to be being updated. The last saved date on the 2010 file that is xreffed in does not change, but suddenly AutoCAD 2010 starts saying that it was created with a newer version of AutoCAD.
I'm definitely not saving anything, and not ref-editing anything. All I'm doing is viewing the model that happens to contain x-refs. I've also noticed that it doesn't always happen, and it appears that it's only happening to x-refs that happen to pass into the viewport. If I open a file, but don't move around in the model much, and never see any given xref, that file will not get magically upgraded to 2014.
first, confirm all users have the same settings in the Options, Open and Save tab
if one user varies this issue will persist.
regardless of which version or flavor of AutoCAD (2010-2014) AutoCAD MEP or Architectural
it only takes one user to deviate in the settings.
open the files (read only) and save as to the correct version and then xref those files into your working file and the issue should go away as long as ALL users have the same settings.