How to fix PortalTransforms Cannot register transform lynx_dump?

At least for lynx_dump, we solved by doing:

  • sudo apt install -y lynx
  • Execute in a script in bin/instance run or another preferred method:
from Products.CMFCore.utils import getToolByName
portal = app['Plone']
transforms = getToolByName(portal, 'portal_transforms')
name = 'lynx_dump'
if name in transforms.objectIds():
    transforms.unregisterTransform(name)
  • sudo apt remove -y lynx

So, for @GhitaB case or another person with a similar problem, I would suggest installing the not found source of problem (lynx in my case and Ploneboard in GhitaB's case) and then try to unregister the transform.