To place a Marker on a Google Map or an OpenStreetMap use the LocationSensor (a LocationSensor component must be in your app) to return the latitude and longitude. You need the following blocks where you provide as much address information as you can in the TextBox:
Geocoding is the process of converting addresses (like a street address) into geographic coordinates (like latitude and longitude), which you can use to place markers on a map
...this technique works only if you are connected to WIFI or network (because the Google database is consulted to provide the coordinates)... The technique will provide incorrect information if insufficient address information is provided or might not provide an answer if the address is not in Google's database. 123 Mainstreet might not work but 123 Mainstreet Dallas Tx might or 123 Mainstreet London perhaps.
Is this what you want to do? Get this example to work using a real device (it will not work in an emulator) and then possibly you can get other parts of your app to stop spawning errors.
Regards,
Steve