Cannot modify managed object: entity=CustomFieldDefinition, component=00N1t00000xxxx, field=Description, state=installed: newValue='null', oldValue='XXXXXXXX'
I got this error when I do validation via ant tool. This is because of latest managed package version has description field value and old one doesn't. So I have added description as in latest version to my file(file given for validation) after that I got below error,
Cannot modify managed object: entity=NamedFilter, component=null, state=MANAGED_INSTALLED - filters