This is a recent problem which has started occurring since moving to Win 10.
When using 3D analyst to draw a line ('Interpolate Line') to get a profile graph of a section of a DEM, ArcGIS crashes completely when attempting to draw the profile graph (regardless of length). I also notice that the other two options 'Point Profile' and 'Terrain Point Profile' are greyed out which was not the case in Win7
Lots of available space in Default.gdb location - even tried setting a different Default.gdb in case this was the problem.
Running Win10 Enterprise / Build 3.25 / 64GB RAM
ArcGIS Desktop 10.5.1(.7333) / Advanced
Sorry that you're running into a crash. Have either of you reported this to technical support? When there are reproducible steps that cause a crash, the best way to get that to the development team is by reporting a crash bug.
Or have you submitted the error report along with your email address?
Here's a bit about why these things are important: ArcGIS Desktop Error Reporter Learns Its Manners
I don't have quick access to ArcMap 10.5 but quickly tested creating a profile graph from the 3D Analyst toolbar just now in ArcMap 10.7.1 and it doesn't crash.
If you have steps that reproduce the issue, please share those here and we can try again. If you have the ability to upgrade to 10.7.1, do that and try your steps again and follow up here with the result.