Missing module pyexpat for launching JupyterLab after updating Anaconda

Question

After updating anaconda last version with conda update -n base Jupyter lab launched from an environment (called md) doesnt start anymore. `

Traceback (most recent call last):
  File "C:\Users\user\anaconda3\envs\md\Scripts\jupyter-lab-script.py", line 5, in <module>
    from jupyterlab.labapp import main
  File "C:\Users\user\anaconda3\envs\md\Lib\site-packages\jupyterlab\labapp.py", line 45, in <module>
    from .extensions import MANAGERS as EXT_MANAGERS
  File "C:\Users\user\anaconda3\envs\md\Lib\site-packages\jupyterlab\extensions\__init__.py", line 12, in <module>
    from .pypi import PyPIExtensionManager
  File "C:\Users\user\anaconda3\envs\md\Lib\site-packages\jupyterlab\extensions\pypi.py", line 13, in <module>
    import xmlrpc.client
  File "C:\Users\user\anaconda3\envs\md\Lib\xmlrpc\client.py", line 138, in <module>
    from xml.parsers import expat
  File "C:\Users\user\anaconda3\envs\md\Lib\xml\parsers\expat.py", line 4, in <module>
    from pyexpat import *
ImportError: DLL load failed while importing pyexpat: The specified module could not be found.

I later update the env md too but it reports the same error again. It seems that a module pyexpat is missing. The jupyter lab is also missing in the Anaconda Navigator's window of the env md. If I launch JL from base (root) it starts. I update the navigator too but the situation isnt changed. How can I solve this?