This message has a repeating group of two MDEntries. Field 290 appears in the first one, but not the second one. Your code is probably trying to extract 290 from the second one, and is thus getting the error.
Group 1 (has 290):
279=2☺55=ZN☺48=00A0IN00ZNZ☺10455=ZNU3☺167=FUT☺207=CBOT☺15=USD☺200=201309☺290=1☺269=0☺270=126.4375☺271=9☺387=12237☺
Group 2 (lacks 290):
279=0☺269=0☺270=126.421875☺271=57☺
Examine your code that's extracting 290. Put in an if-field-is-present check so that it doesn't try to extract a field that's not there.