Some data in my Adoption Content pack corrupted?

Jenny Sinclair
New Contributor

I have been happily using the adoption pack for a couple of years now and use the basic OOTB dashboard that was provided and haven't changed it.  About 6 months ago, one of the items on the dashboard entitled "Exchange - Online storage used" came up with an error of "Can't display the visual".  When I try to create a new custom report using the Field Group "TenantMailboxUsage" and the fields "EXO-Storage(%)" or "EXO-StorageUsed", which would be the fields feeding the dashboard element, then I get the same error "Can't display the visual" and the details are: "Couldn't load the data for this visual.  The query referenced calculated column 'TenantMailboxUsage'[DiskUsedbyStorageType] which does not hold any data because evaluation of one of the rows caused an error."

I'm not particular technical so any suggestions that don't assume a huge amount of tech savvy would be welcomed