V7.3.4 upgrade issue - forum stopped working

I had successfully performed the upgrade from V7.3.3 to V7.3.4 in my dev environment. After that, I attempted the same in the production environment. Everything went fine until I attempted to recompile forum languages. The forum module stopped working altogether showing HTTP ERROR 500. I could figure from modules/boonex/forum/error_log that some many of the php class files of the module, especially the ones in the modules/boonex/forum/classes/en directory got corrupted, i.e. some unnecessary lines got appended at the end of the files. I tried replacing individual files from the corresponding path of my dev instance. That only partially restored the module. Finally, I got the Forum module working by deleting the modules/boonex/forum directory altogether in the production instance and copying over the same from dev instance.