A store request failed because one of the records that is transferred is too short for the destination data set. This error occurs when the destination data set is a fixed record format, the transfer mode is b (blocked) or c (compressed), and a short record is transferred. The C run-time errno code of 4 says that a specified record length is not large enough.
FTP continues.
Ensure that each fixed format record has the correct length or choose a non-fixed record format (for example, a variable).