Can't update Anaconda

Since I can’t update conda itself, I tried to update anaconda. This also fails with

Unpacking payload ...
concurrent.futures.process._RemoteTraceback:                                                                                                                                           
'''
Traceback (most recent call last):
  File "concurrent/futures/process.py", line 387, in wait_result_broken_or_wakeup
  File "multiprocessing/connection.py", line 256, in recv
TypeError: __init__() missing 1 required positional argument: 'msg'
'''

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "entry_point.py", line 69, in <module>
  File "concurrent/futures/process.py", line 562, in _chain_from_iterable_of_lists
  File "concurrent/futures/_base.py", line 609, in result_iterator
  File "concurrent/futures/_base.py", line 446, in result
  File "concurrent/futures/_base.py", line 391, in __get_result
concurrent.futures.process.BrokenProcessPool: A process in the process pool was terminated abruptly while the future was running or pending.
[2030952] Failed to execute script 'entry_point' due to unhandled exception!