Mindmanager export / publish result in error on opening html5

1. I created a mindmap, published it and opened the published result.
2. The weblink for the published map told me it was downloading; this is business as usual;
3. When finished, it should display, my map; instead it showed a dialogue box with the text: "TypeError: n.requestInfoFrameUpdate is not a function"; I then only could cancel.

HOWEVER:

• When I changed my original mindmap and deleted all topics except the central one; I could publish it (with the same link as before), it was downloaded and showed me the 1-topic map without any problems.
• When I opened this 1-topic map with MM24, added a topic and published an update again, opening the published map resulted in the same problem.
• When (back in MM25) I created a new map from scratch, published the central topic, added a subtopic and updated the published map, all works fine (as it should). So my conclusion is there is whatever error om the first file i worked with.
• Of course, you now could conclude: switch with a new file and a new publishing action. However, that also results in a new publication link, while i have reasons to stay with the earlier one.

Please, advice!