Unable to load the specified metadata resource && the assembly specified does not exist in the assemblies enumration

Question

I'm facing this error while using EntityDataSource

Solutions I've tried
1- Built the solution 'ctrl + shift + B'
2- In web config file changed the resources
From

"metadata=
     res://*/GreenCityModel.csdl|
     res://*/GreenCityModel.ssdl|
     res://*/GreenCityModel.msl;provider=

To

"metadata=
     res://GreenCityChiniotWeb/GreenCityModel.csdl|
     res://GreenCityChiniotWeb/GreenCityModel.ssdl|
     res://GreenCityChiniotWeb/GreenCityModel.msl;provider=

"GreenCityChiniotWeb" is my correct assembly name which I'm pretty sure. after applying this solution error slightly changed

3rd solution I tried was so called worst case by using only *

<add name="GreenCityChinyotDbEntities" connectionString="metadata=
    res://*/;provider= <!-- ... -->

than there were no errors thrown, but the "DefaultContainerName:" combobox remained empty

what else can i try?