The bug is essentially a problem with the Tree and Body control with the "Display properties" window open. Could we verify in other platforms?
Very simple to test:
Create a new file and a Body.
Right-click the Body in the tree and select Appearance, the "Display properties " opens, keep that window open.
Select Body in the tree and rename it.
That's where the problems starts on my Windows machine. When I hit Enter the Body text field does not close correctly, properties don't show, many different screen things don't work correctly.
I presume the programmers expect the Display properties window to be closed but there are no interlocks to guarantee.
Thanks
OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.14709 (Git)
Build type: Release
Branch: master
Hash: faad5ea27301cb7af393a25d317c406d3098bafe
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)