SharePoint 2010 feature upgrade - null reference exception

H!

I am trying to upgrade my custom feature. Upgrade action definition is following:

  <UpgradeActions>
    <VersionRange BeginVersion="0.0.0.0" EndVersion="1.0.0.0">
      <ApplyElementManifests>
        <ElementManifest Location="MyNewContentTypes\Elements.xml" />
      </ApplyElementManifests>
    </VersionRange>
  </UpgradeActions>
Update-SPSolution is executed without any errors, but when I try to upgrade feature I get following error:

- System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SharePoint.Utilities.SPUtility.XmlGetAttrVal(XmlNode xn, String attr) at Microsoft.SharePoint.SPApplyElementManifestsUpgradeAction.get_ElementManifests() at Microsoft.SharePoint.SPApplyElementManifestsUpgradeAction.Upgrading(SPFeatureReceiverProperties props, SPWebApplication webapp, SPSite site, SPWeb web, Boolean fForce) at Microsoft.SharePoint.Administration.SPFeatureDefinition.UpgradeCore(SPFeature feature, SPWebApplication webApp, SPSite site, SPWeb web, Boolean fForce)

As far as I understand something is wrong with ApplyElementManifests element, but it seems OK... Any help is appreciated. Thanks!