Kicad crashes when removing aliases

I want to customize the symbol Relay:RTE4xxx, so I do the following:

  1. Open Symbol Editor
  2. Edit Relay:RTE4xxxx
  3. Save as: mylibrary:RT444024
  4. Edit properties: Aliases > Delete alias
  5. Click Ok

Kicad crashes. I did this dozen of times and the behavior is always the same…

Kicad version info:

Application: LibEdit
Version: 5.1.9-73d0e3b20d~88~ubuntu20.04.1, release build
Libraries:
wxWidgets 3.0.4
libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3
Platform: Linux 5.4.0-65-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
Boost: 1.71.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.68.0
Compiler: GCC 9.3.0 with C++ ABI 1013

Build settings:
USE_WX_GRAPHICS_CONTEXT=OFF
USE_WX_OVERLAY=ON
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=ON
KICAD_SCRIPTING_PYTHON3=ON
KICAD_SCRIPTING_WXPYTHON=ON
KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=ON
KICAD_USE_OCE=ON
KICAD_USE_OCC=OFF
KICAD_SPICE=ON

Not sure how to fix it, but tried here and don’t have any issues.
(Same version of Kicad and Ubuntu)

I suffered this problem some time ago: once and only once and I have never been able to duplicate the problem.

In case anyone is curious, this was the story:
I had a brand new C drive onto which I loaded Linux Mint.
After poking around with that OS for a little while I downloaded the then new Kicad 5.1.9.
Next I checked that I could find and open my Kicad circuit files that live on D drive.
Next I started a new project. Then a new personal global library.
Then: Open symbol editor
Edit part and rename from Kicad library.
Save to my new library.
Save file
Open new part in my new library.
Edit aliases: deleted about 10 aliases.
Click OK then complete Kicad crash.
Second attempt, same result.
Checked new library to make sure no typos in the path.
Third attempt I only deleted one alias. Kicad thought about this for about two seconds then deleted the one alias.
Fourth attempt I deleted the other nine aliases and the programme worked properly, instantly and has never faulted since.

Spent a good hour yesterday trying everything I could think of to help the OP but just couldn’t repeat the fault.