It would be interesting to know what happened. It's always hard to know how much to reveal about one's internal processes to customers, but this does seem like a pretty big thing (named instances) to have slipped by QC and regression testing. We've all let things like this slip by, and it's helpful and humanizing sometimes to reveal where the lapse happened and why.
We seem to have an new but simmilar problem now
Invalid Mashup Expression using supplied values. inner exception: An error happened while reading data from the provider: 'Instance failure.'
Please can you check this
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Features releasing from October 2019 through March 2020