pop from empty list ???

[gamafreire]

Hello Juergen,
I consistently turn to your project among all the physical quantity packages. Thank you for your contribution.

Recently, I discovered that a code, which had been running smoothly before, started to produce an error after executing the initialisation command:

%load_ext PhysicalQuantities.ipython

The conclusion of the error list is as follows:

In an effort to avoid overwhelming you with information, I conclude my message with the hope that you can assist me. However, I am at your disposal to provide any additional information you may require.

Best regards
Filipe