The c89 command tried to dynamically allocate the data set name indicated and to associate it with the indicated data definition name. The dynamic allocation failed, because the data set indicated could not be found. This is probably because the data set does not exist, or is not correctly cataloged (c89 can only work with cataloged data sets). Note that for data set names specified on the c89 command line, unless the data set name is enclosed in single quotes, a TSO/E user ID prefix is added to the data set name.
In the message text:
string1 is the data definition name. string2 is the data set name.
c89 "//'myuser.myprog.c'"