I had x y z axis listed under the origin in the features tree. Today they are suddenly all gone. How can I bring them back?
1) You are using the same part file template, and
2) No one else has altered the template
OR recreate them simply:
Rollback to Origin.
Select Top Plane & Front Plane. Create Axis. Name it X-axis.
Select Front Plane & Right Plane. Create Axis. Name it Y-axis.
Select Right Plane & Top Plane. Create Axis. Name it Z-axis. (Put these in a folder if you wish)
Roll forward to end.
Is this in the same file? Or did you create them in one file and want to use them in another one?
They are missing from the newly created parts. All previous parts still have them.
Then it sounds like they weren't saved in your Part Template. See #26 at FAQ - Part 2.
Retrieving data ...