No changes to the code were made. The module has not been installed for 1-2 years. DB2 and LE have most likely been upgraded. DB2 is v11. In the compile step, getting "CONSTRUCTION ERROR IN DB2, RC = 12".
The compile step uses the libraries below and they should be checked that they exist, have space, and directory blocks.
Cobol Source library
Internal and Compatibility NCAL load librairies
Foreign Internal and Compatibility NCAL load libraries
DB2 Precompiler and Compiler libraries
The correct compiler library and version listed in PARMLIB(TIRHE)
The cause of the error is a problem with one of the libraries above.
RESOLUTION 1: Fix the problem with a library.
RESOLUTION 2: The precompiler version is incorrect. To know this, create and insert a LISTINGS dataset in the construction library and compile the failing module. The compile listing will tell you the version of the precompiler and compiler. Update PARMLIB(TIRHE) with the correct compiler library or make the necessary changes to the DB2 library. See your DBA.