Hello everybody,
I had to change the dataype of a field from Picklist to MultiSelectPicklist. I did so on the development environment, exported the solution as a managed solution. When trying to import it into the managed Test system the import fails with the error message ."Attribute <fieldname> is a Picklist, but a MultiSelectPicklist type was specified."
How can I import a solution with modified type specifications? I tried update ("replaces your older solution with this one" - I expect this to work for modifications of datatypes ) and and upgrade and both failed.
Is there a way to get the modification transferred to the managed solution?
on development system from where the export is done:

on test system

This should be replaced.
Any hint/help would be very much appreciated.
Kind regards