Prodcution cube error in AX 2012

1. An error occurred while processing the 'Exchange rates by day' partition of the 'Exchange rates by day' measure group for the 'Production cube' cube

2.  Null value is eliminated by an aggregate or other SET operation.; 01003; The conversion of a nvarchar data type to a datetime data type resulted in an out-of-range value

Can any one suggest what actions need to be taken to resolve these errors.

Thanks in advance.