Could you tell us the main difference between XML objects from the V11 to the V12.
We have seen some difference between V12 xml exports because they cannot be imported under the V11.2
When we try to import a V12 XML exported object to a V11 we have the following error message:
U04005869 The existing version '12.0.1+build.611' of the export file is not compatible with the current version '11.2.3+build.465'!
To bypass it, you should edit the XML file and replace the Version 12 by 11 inside the tag "uc-export clientvers "
Like this, you will be able to import it.