... if this is of any value ... here is some additional info from the report file generated just before the error above is seen:
Source Context :
SourceModule : [er.main]
SourceID : [/home/ecloud/workspace/Build_OpenSys_r188.8.131.52.0_078_/perforce/src/app/er/rep.c]
SourceFunction : [get_infile_params]
SourceLine : 
Yes this error has been observed when there are differences in formats between DEFGEN versions. This is discussed in the following Knowledge article on MOS:
Replicat abend with ERROR OGG-00303 Problem at line xx. Expecting file, table, or record definition. (Doc ID 1455370.1)
In OGG 11.2, there is a new parameter NOEXTATTR. This is used in DEFGEN. When the OGG version in a target site is lower than the source site, defgen needs to use parameter NOEXTATTR to generate a sourcedef file which target site can read . If using a sourcedef file generated without NOEXTATTR, a replicat will abend with error 00303.
So there are two ways to get around the issue:
1. Use a defgen paramfile with NOEXTATTR option, or
2. Generate definition file with the same OGG version as the OGG target site version.