Interesting. There isn't one sentence in that article (English) which describes the political controversy of that movie. A single sentence mentions the film almost being banned for its 'political overtones'.

The English article is incomplete. The banner is there. I guess I could try to complete it but it’s highly my work would be struck out by an angry editor feeling territorial for a reason or another so maybe not.

The French article is a bit better - I don’t understand German sadly.

The controversy stems from the protagonists values. They put their love for each other and their search for fulfilment above other commitments which was seen as dangerously non communist. The film was cleared by the head of East Germany but the censors still imposed a tragic ending.