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The company writes:
Many of our clients are affected so I thought I'd raise a note to the community. The issue is only with template sites where the mobile data view was enabled. The feature, now being deprecated, is no longer supported in the template and should be removed.
There are workarounds showing you how to allow the templates to be used, but you're better off saving yourself a lot of time and heartache by solving the template itself, not the host site collection, otherwise you will be forever solving the issue.
Here are some useful links on how to resolve it and why it's happening:
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