Problem
When changing scope in the Desktop Client, you receive an error indicating that "one dataset was expected when updating an object from the database."
Solution
This error can be caused by having multiple worker processes set greater than one on the cache application pool, which leads to having multiple independent caches running on the system that get out of synchronization.
Multiple worker processes are supported only on the main SPFServer service application pool. The maximum number of worker processes that can be configured on the license, cache and configuration service application pools is limited to one. Multiple worker processes are not supported on these application pools. For more information, see Configure maximum worker processes.