I know it's been a while since the question, but does it have anything to do with the closing tag of admNumberMapping that is incorrect? Also check that you don't overwrite the MaxPrecision to 1 but make it 5:
<edmMappings>
<edmNumberMapping>
<add NETType="Int16" MinPrecision="1" MaxPrecision="5" DBType="Number" />
</edmNumberMapping>
</edmMappings>