That’s an error from SSRS, you’ll need to remove that Calc_MtExtPrice field from the report’s dataset. There’s a bunch of threads here that explain how to go about fixing it, this usually happens during upgrades when Epicor makes a bunch of field changes.
I’m not entirely sure how to modify the reports when on cloud, I think the Report Style screen has a download / upload button that gives you an RDL file you then open and edit in Report Builder.