How to open up X4 library in X8

Yes, I am slow to do upgrades.  But I recently upgraded from Endnote X4 to Endnote X8.  I can’t run X4 on Sierra, and when I try to open my old X4 libraries in X8 nothing happens.  (Literally nothing: no error message and no file is opened).  Is there any way that I can save my decades of libraries, or am I just SOL?  Are there any converters out there that could help me?

Thanks for your reply - I am grateful for any attempt to help me and trying to avoid freaking out yet.  Yes, I backed up my libraries.  For the one I’m looking at right now and can’t open (last opened July 2015), yes, I see the .enl file and the .Data folder.  There were no PDF attachments, so that shouldn’t be the issue.  Any other suggestions for me?  Desperate.

In playing around with import/export stuff, I realized that I couldn’t even open up a *new* library in X8.  So I quit the app (had to force-quit, actually) and tried again.  Now it will open up the X4 library.  So, I guess Endnote had just gotten itself into a funny state.

So, of course, the answer was, as always: “Try turning it off and on again.”

Same issue for me - old Mac broken, new one required update to Sierra and Endnote X8.

Importing seemed to work (took quite some time), but in the end I was told that the library “is in use by someone else”.

What else can I do?