Running SAPUI5 app with MockServer , it gives error :- resource URL '' has unknown type

i'm trying to run UI5 fiori element app with mockserver but it is giving following error after i run it :-

Uncaught Error: resource URL '' has unknown type (should be one of .properties,.hdbtextbundle) at s (ResourceBundle-dbg.js:202) at new R (ResourceBundle-dbg.js:244) at Function.R.create (ResourceBundle-dbg.js:584) at Function.b.loadResourceBundle (ResourceModel-dbg.js:393) at _ (ResourceModel-dbg.js:573) at new constructor (ResourceModel-dbg.js:278) at Object.r.getTranslationModel (Bookmark-dbg.js:543) at eval (ClientSideTargetResolution-dbg.js:42) at ui5loader-dbg.js:1834 at requireAll (ui5loader-dbg.js:1757)

Also few "Failed to load resource: the server responded with a status of 404 ()"