Conflict between default and conda-forge

I wanted to load some packages from condo-forge (PlasmaPy and Veusz), and added that to my Channels, but when I do, the default channel packages (Jupyterlab, et al.) disappear in the environment. I tried loading with condo-forge, then deleting the channel, but then Veusz will not load, although it does stay in the Home display.
This is on a Mac, 11.6, Anaconda 2.1.4

Thanks for your question! Based on what you’re describing, I would expect the Anaconda default version packages to be replaced by the conda-forge version of those packages - not disappear altogether. Though we would like both channels to be completely compatible - right now that is not the case. Can you include the output of conda list --show-channel-urls and conda info?