UC_OBJECTS_NOT_CONVERTIBLE dump while viewing PSA DATA

hi experts,

i am extracting data from ECC, the data source is 2lis_02_itm.

i have added KNUMV field to my extract structure from POOL. i can see the data in RSA3 for the data source.

i replicated into BW and trying to extract the data. extracting successfully but when i try to see the PSA data its giving the dump UC_OBJECTS_NOT_CONVERTIBLE.

when i right click data source and manage, try to see the data its giving the below error.

Field STRU_D99C0Y2D2K3WZRDBR9N83MAUI-KNUMV is not

in the ABAP Dictionary.

but i have checked the transfer structure the field KNUMV is active.

what is the solution and wot could be the issue.

regards

venuscm