Problem filtering data relations with RESTful API

I have my data relations setup on the Telerik backend and I need to filter them based on a user's selection. When I add a filter(id) I get an error.

DataRelations:

https://api.everlive.com/v1/zqptwkzq293nmpyn/Systems?expand={"Service_Rel":{"TargetTypeName":"Systems"}}

Selecting a single item returns an error using the RESTful API but works fine in this URL:

https://api.everlive.com/v1/zqptwkzq293nmpyn/Systems/43440bf0-52b5-11e6-a2d0-bd4b32a72243?expand={%22Service_Rel%22:{%22TargetTypeName%22:%22Services%22}}

Any help is greatly appreciated.

MS