A RESTRUCTURE to increase the size of an existing record abends with S0C1.
A possible reason for the S0C1 can be a missing MINLEN parameter in the RECNAME clause of the IDMSRSST macro. Without the max-data-length in this parameter the storage for the record is allocated with the old record max length. The new fields are built behind the record and if the allocated storage is too small the storage behind is overwritten overlaying working storage of the RESTRUCTURE modules. This results in abends like S0C1.
For variable length record you have to add a MINLEN parameter in the IDMSRSTT RECNAME statement. The max-data-length of the MINLEN parameter is used by RESTRUCTURE to compute the new record length.
This error only happens if you code the IDMSRSTT macros directly. If you use the IDMSRSTC utility to generate the IDMSRSTT macro statements, the MINLEN will always get generated.