If I recall correctly, this only started after the last Messenger update.
I think we need to update the Plus! version. I know Metro is set to version 5.01, which is now old
Hence if you want, go to the skin's folder and find SkinInfo.xml, and change
XML code:
<PlusSkin>
<ResGroup>
<PlusVersion Major="5" Minor="1"/>
to
XML code:
<PlusSkin>
<ResGroup>
<PlusVersion Major="5" Minor="2"/>