Skip navigation
All Places > FAQs (Frequently Asked Questions) > Blog > 2017 > December > 22

SolidWorks files can't be opened with an earlier version than the one they were last saved with, and they can't be saved back so an earlier version can open them (except as a dumb solid; see two paragraphs down).  I know that isn't true for many programs, such as Word, Excel, etc., but SolidWorks is many times more complex than these programs, and features may have been created with functions that weren’t available in earlier versions, and there are probably other reasons.  I think Ryan McVay gave one of the best explanations I've seen in the Discussion I link to a few paragraphs down: "Well, because this would require the software to bear the burden of including feature checks, older code, extra code to do the checking and converting, extra Parasolid version exporting, and file restructuring, etc. to exist in the software. Your install DVD just went from 4GB to 10GB- oh crap that doesn’t fit on dvd anymore! And this would only increase every version because you are carrying legacy code and export tools. This is one of the many, but a big reason, why you don’t have backward compatibility across all CAD packages and why users rely on neutral solid exports like STEP and Parasolid- outside of the kernel and 3d definition."


People have been asking for backwards compatibility for years, and maybe someday it will happen, but it hasn’t yet.  Document templates are also not backwards compatible.  If a template was saved with SW2015 you won't be able to start a new drawing, part, etc. with it using SW2014.  Service packs are backwards compatible within the same version.  For example, a file saved with SW2014 service pack 5 can be opened with SW2014 service pack 1.


SW models may be saved as several forms of dumb solids, and then opened with earlier versions, but they will lose the features in the tree.  According to Jim Wilkinson (and he would know), Parasolid is your best option when doing this.  His response at Re: compatibility between versions  was "If you do this, make sure to use Parasolid.  Parasolid is the native format of SOLIDWORKS so there is no translation when going back. STL is DEFINITELY a bad choice because it only transfers tessellated data which is nearly useless compared to the original b-rep solid/surface data."


SW2013 introduced the ability to open files one level newer with service pack 5, and use these files in assemblies, but that has limited functionality (see 2016 SOLIDWORKS Help - Future Version Components in Earlier Releases for more information).  Due to an architectural change in SW2015 that ability was suspended for one year.  It was supposed to be re-instated with SW2016 (see Jody Stiles reply here:Will solidworks 2016 files work with 2015?), but when I checked it didn't seem to be working for me.  I never use it anyway, so it hasn't been an issue for me.


Occasionally someone will ask if there's a way to tell which version was used to save a file if you can't open it.  Yes, there is.  In Windows Explorer, browse to the folder containing the file.  Right-click on a blank space at the top, beside the column names, and choose "More..."



Select "SW Last saved with".




That will add a column indicating which SW version last saved the file.




  By the way, I believe in giving credit where it's due, and I wouldn't want anyone to think I'm smart enough to have figured this out for myself.  I learned about it in a post by Steve Calvert at Can you tell what SW version a model was created with?

Assemblies that have some movement, such as a hydraulic cylinder or hinge, are by default rigid when inserted into another assembly, but they can be made flexible.  Find the sub-assembly in the upper-level assembly tree and click on it.  Choose the "Make Component Flexible" icon.  It should now have the same amount of freedom that it had in it's own file.


I believe this icon was first available with SW 2014.  If you're using an earlier version you will need to choose the “Component Properties…” icon instead.


That will take you to the Component Properties dialog box.  “Rigid” will be selected by default in the “Solve as” section.  Select “Flexible” instead, then “OK”.


By the way, if you have a Limit Mate in your sub-assembly it may be broken when you insert it into the main assembly.  If that happens, delete the Limit Mate from the sub-assembly and apply it in the top level assembly instead.  I rarely use Limit Mates, but I have seen reports on the Forum that this was much improved with SW2016, so if you're using 2016 or later you might give it a try.

Jim Wilkinson

Call for FAQs

Posted by Jim Wilkinson Dec 22, 2017

If you have a suggestion for an FAQ that should be added to this area, post the suggestion as a comment to this post. It will be reviewed and if it is FAQ-worthy, we will add it to the list of FAQs to be added.

This space in the forum is used to document FAQs (Frequently Asked Questions) about the forum itself and the SOLIDWORKS software. Most blogs in the forum are limited to SOLIDWORKS employees posting. But, since Glenn Schroeder took his own initiative to create FAQs using regular discussions, he also has permission and most of the initial content for these FAQs came from Glenn's FAQ posts. Dan Pihlaja has also been added as a FAQ contributor due to his excellent post on using the forum and other helpful posts. Thank you Glenn and Dan for your hard work and dedication to the SOLIDWORKS community!


Each FAQ has one or more category assigned to it to aid in browsing and searching the FAQs. On the space homepage (FAQs (Frequently Asked Questions)) there is also listings for:

  • Sticky FAQs which are manually selected/listed by forum moderators. These hopefully make up for the fact that the forums themselves don't have "sticky posts".
  • Popular FAQs which the forum automatically populates based on users visiting the individual FAQs


We will continue to look for other ways to creatively use the FAQs in the forum.


If you have suggestions for use of FAQs on the forum or the FAQ space itself, post those suggestions in a comment to this post.

If you have suggestions on actual FAQs that should be added, see this blog post: Call for FAQs