When placing a transfer order you have the option of selecting the bin you wish to transfer from. If you have selected a bin in this field and there is no stock in the bin OR you have selected a serial number which is not in that bin you will not be able to pick the order even though the order is at RTP status.
The order is at RTP status because it can be fulfilled from another bin location.
To resolve this issue;
1. Double click on the transfer in the transfer register or right click on the transfer in the despatch register and select drill to source to open the transaction entry form.
2. Remove the bin and batch information and manual type in the number to be transferred.
3. Continue to pick the order as normal.