In our Sandbox account we are trying to add an item to the basket but get this error? The TAX Code is correct on the item. Any ideas?

Check for Scriptable Cart. 1. Look if Setup->Website->your site->Scriptable Cart and checkout is checked. 2. If it is, check any client scripts deployed to the Sales Order record (or in the scripting template forms) because they might be executing and triggering tax code changes.

Same on 10 script limit. A few dev scripts were triggering. Thank you!