Before trying anything, was it working before? Have you recently upgraded/updated and not restarted everything? Does JupyterLab work? If you haven’t invested a lot in environments on this machine yet, you may want to try uninstalling Anaconda and cleaning and reinstalling first.
You may want to see here or the latest ones here or this point in this thread and suggestions below there for some options to try.
(Someone posted a similar issue here last month that you may want to monitor, too.)