If you get a cryptic linux error message similar to:
<application>: /lib/tls/libc.so.6: version `GLIBC_2.4' not found (required by <library>)
<application>: /lib64/tls/libc.so.6: version `GLIBC_2.4' not found (required by <library>)
while running a 2011/2012 release of some Cadence tools on Linux, it means you are using the wrong OS (most likely trying to run on RHE40 or equivalent).
Note: EDI11 and IC616 are some of the tools that require RHE50 or higher/compatible to run.
You can check the following post for more details.