This bug is probably related to bug SNAP-3902 listed on JIRA. I am unable to create an issue there.
SNAP 12 installed on Linux fails to open Sentinel-1C products. This is the case on two completely separate systems that I tried, one running Rocky Linux release 8.8 (Green Obsidian), the other running CentOS 7.8.2003.
When trying to open manifest.safe, the following error is written to messages.log:
WARNING [eu.esa.snap.hdf.HDFLoader]: class eu.esa.snap.hdf.HDFLoader:
HDF-5 library not available: class java.lang.UnsatisfiedLinkError: 'int
hdf.hdflib.HDFLibrary.HDdont_atexit()'
WARNING [eu.esa.snap.hdf.HDFLoader]: HDF/HDF5 dependent readers disabled.
SEVERE [global]
java.lang.IllegalStateException: HDF5 NOT initialised! Check log for
details.
at
eu.esa.snap.hdf.HDFLoader.ensureHDF5Initialised(HDFLoader.java:36)
The same file opens without problems in SNAP 11 when installed on the same system.