I have been experiencing the same issues as stated above. It may be easy to reset and remap but this is a costly process when you have very wide tables with multiple data conversions. I had a mapping where I changed the datatype on a string to dt_dbdate. The data type in the destination was datetime so I changed it to date to match. When I try to run the package I receive errors that it won't convert to a DT_WSTR?

I tried the solution above to reset everything but am still seeing the issue. My resolution was to use the OLE DB destination instead of SQL Server destination and it will now allow for the change I made in my destination.