Legacy custom office UDFs should convert to framework custom office UDFs in the migration and data conversion processes.    You shouldn't need to import them.

Thanks for the quick response Natasha.  I have a file, SO_LU_SO2LineUdfFile, from vers. 4.05 that contains 6 UDF's.  Are you saying that these will be pulled across in the conversion process into the Sales Order Detail table in 4.5?  We've gone through the conversion routine a few times here (in our test company) but we've never seen our "new" UDF's in 4.5 populated (we have defined the 4.5 fields with the same name and same data type as our 4.05 UDF's).  

I always assumed we'd have to import the old values into the new UDF's via VI.

That isn't a standard S/O table name.  You need to determine who supplied that enhancement and contact them about upgrading.

dstout66,

SO_LU belonged to Extended Solution SO-1014.  The standard company data converion process should create new UDF fields and convert the data.   We convert all Extended Solutions UDF fields and data to business framework. 

SO-1014 needs to be enabled in 4.05 when you upgrade.

If you are customized by master developer (not Sage Extended Solutions), then there is no guarantee.