This error can occur for a couple of reasons
first there is actually no EAC reference in the related object ie. AWE0910.xml has a href to http://nla.gov.au/nla.party-544549 but that site doesn't have an EAC tag in the metadata. In this case the message is correct but this should not raise an IOError
the second case is where the reference actually does have an EAC tag but the file it points to is missing ie. AWAP/biogs/AWE0569b.htm has a valid EAC tag which maps to AWAP/eac/AWE0569.xml but that file does not exist. In this case the IOError is valid but the message is incorrect
https://github.com/esrc-unimelb/CNEX3/blob/867a7a88a0c2b67686e344623a08d204a0bf06a4/service/app/Entity.py#L153
This error can occur for a couple of reasons first there is actually no EAC reference in the related object ie. AWE0910.xml has a href to http://nla.gov.au/nla.party-544549 but that site doesn't have an EAC tag in the metadata. In this case the message is correct but this should not raise an IOError
the second case is where the reference actually does have an EAC tag but the file it points to is missing ie. AWAP/biogs/AWE0569b.htm has a valid EAC tag which maps to AWAP/eac/AWE0569.xml but that file does not exist. In this case the IOError is valid but the message is incorrect
too much going in the one try block...