Hello @joNic, there have been a few occasions where I have replaced a dataset like that on a dashboard and it did not maintain my calculated fields. Is it possible that calculated fields required for the visuals are not showing and that is why the visuals are displaying an error? If not, are you ignoring any of the fields from the original dataset when you map the new dataset as a replacement?
Those are the only issues I can think of for this if the dataset is working as expected in a new analysis. I suppose the other possibility is that fields are not mapping correctly when you replace the dataset. Let me know if any of those issues I mentioned are occurring and we might be able to figure out a solution.