I created a new website through the administration interface and I can't access another website that already existed.

I created a new website through the Plone administration interface. I am not able to access another site that already existed.

The plone is v5.2, it is running in a docker container and Zope 4.

The error shown is:

Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 155, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 337, in publish_module
  Module ZPublisher.WSGIPublisher, line 255, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 61, in call_object
  Module z3c.form.form, line 233, in __call__
  Module z3c.form.form, line 228, in update
  Module plone.app.z3cform.csrf, line 22, in execute
  Module z3c.form.action, line 98, in execute
  Module z3c.form.button, line 315, in __call__
  Module z3c.form.button, line 170, in __call__
  Module Products.CMFPlone.browser.login.login, line 178, in handleLogin
  Module Products.CMFPlone.browser.login.login, line 135, in _post_login
  Module Products.CMFCore.MembershipTool, line 129, in getAuthenticatedMember
  Module Products.CMFCore.MembershipTool, line 152, in wrapUser
AttributeError: __contains__

Does anyone know what may be causing it?

You created a Plone site within an existing Plone site?

What is the URL of this administration interface? Is it localhost:8080 or something like localhost:8080/Plone/manage_main ?

Is it like localhost:8080.

Where there is the option to create a new website.

After the new website is created, the url is localhost: 8080/plone-site

Please describe exactly what you have done and what exactly caused the error. We must be able to reproduce this error in order for giving help.
Again the question: did you try to create a Plone within a Plone site?

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