Import (Update) of managed Solution fails: ErrorCode 0x8004F024

Hello Everyone,

I get an error while updating our production system:

<Data ss:Type="String">0x8004F024</Data>
<Data ss:Type="String">Cannot update solution 'sws_customization_v1' because it is a managed solution.</Data>

I exported the solution as usual as a managed solution and when updating the solution on the target I get the error

What can I do to investigate this issue further?

Here are some interesting lines of the update log:

<Row ss:AutoFitHeight="0" type="Einfügung von Stammkomponenten">
</Cell>
<Cell ss:StyleID="s137" name="Status">
<Data ss:Type="String">Fehler</Data>
</Cell>
<Cell ss:StyleID="s137" name="ErrorCode">
<Data ss:Type="String">0x8004F024</Data>
</Cell>
<Cell ss:StyleID="s137" name="ErrorText">
<Data ss:Type="String">Cannot update solution 'sws_customization_v1' because it is a managed solution.</Data>
</Cell>
</Row>

"Einfügung von Stammkomponenten" means something like "insert root components"

Thanks in advance!

Kind regards

Alexander