That's strange.
I get exact same error only when I don't import the PS environment script. See below :
Before sourcing PS environment script
[root@shruj01-I1850 bin]# ./XPSRegClient
./XPSRegClient: error while loading shared libraries: libsmi18n.so: cannot open shared object file: No such file or directory
After sourcing PS environment script
[root@shruj01-I1850 bin]# source ../ca_ps_env.ksh
[root@shruj01-I1850 bin]# ./XPSRegClient
[XPSRegClient - XPS Version 12.7.0000.1194]
Log output: /opt/CA/siteminder/log/XPSRegClient.2017-09-05_201455.log
Are you able to start policy server ?
Can you try running ldd against XPSExplorer ?
[root@shruj01-I1850 bin]# ldd XPSRegClient
linux-vdso.so.1 => (0x00007ffe6ad34000)
libsmi18n.so => /opt/CA/siteminder/lib/libsmi18n.so (0x00007f994c9b5000)
libicudata.so.56 => /opt/CA/siteminder/lib/libicudata.so.56 (0x00007f994afd1000)
libicui18n.so.56 => /opt/CA/siteminder/lib/libicui18n.so.56 (0x00007f994aa96000)
libicuio.so.56 => /opt/CA/siteminder/lib/libicuio.so.56 (0x00007f994a888000)
libicuuc.so.56 => /opt/CA/siteminder/lib/libicuuc.so.56 (0x00007f994a49a000)
libXPSTools.so => /opt/CA/siteminder/lib/libXPSTools.so (0x00007f994a1ad000)
libXPSEval.so => /opt/CA/siteminder/lib/libXPSEval.so (0x00007f9949eb2000)
libXPS.so => /opt/CA/siteminder/lib/libXPS.so (0x00007f9949a2b000)
libXLogger.so => /opt/CA/siteminder/lib/libXLogger.so (0x00007f994981d000)
libldap60.so => /opt/CA/siteminder/lib/libldap60.so (0x00007f99495ea000)
libssldap60.so => /opt/CA/siteminder/lib/libssldap60.so (0x00007f99493dd000)
libssl3.so => /opt/CA/siteminder/lib/libssl3.so (0x00007f9949193000)
libprldap60.so => /opt/CA/siteminder/lib/libprldap60.so (0x00007f9948f8e000)
libnss3.so => /opt/CA/siteminder/lib/libnss3.so (0x00007f9948c5b000)
libnspr4.so => /opt/CA/siteminder/lib/libnspr4.so (0x00007f9948a20000)
libnssutil3.so => /opt/CA/siteminder/lib/libnssutil3.so (0x00007f99487f6000)
libplds4.so => /opt/CA/siteminder/lib/libplds4.so (0x00007f99485f2000)
libGCL.so => /opt/CA/siteminder/lib/libGCL.so (0x00007f99483e7000)
libsmcommonutil.so => /opt/CA/siteminder/lib/libsmcommonutil.so (0x00007f994819a000)
libSmXlate.so => /opt/CA/siteminder/lib/libSmXlate.so (0x00007f9947f78000)
libsmerrlog.so => /opt/CA/siteminder/lib/libsmerrlog.so (0x00007f9947c9a000)
libSmShutdownManager.so => /opt/CA/siteminder/lib/libSmShutdownManager.so (0x00007f9947a92000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f9947857000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f9947653000)
librt.so.1 => /lib64/librt.so.1 (0x00007f994744b000)
libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f9947141000)
libm.so.6 => /lib64/libm.so.6 (0x00007f9946e3f000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f9946c29000)
libc.so.6 => /lib64/libc.so.6 (0x00007f9946867000)
libsoftokn3.so => /opt/CA/siteminder/lib/libsoftokn3.so (0x00007f9946627000)
libplc4.so => /opt/CA/siteminder/lib/libplc4.so (0x00007f9946423000)
libz.so.1 => /lib64/libz.so.1 (0x00007f994620d000)
/lib64/ld-linux-x86-64.so.2 (0x00007f994cc1e000)
libsqlite3.so => /opt/CA/siteminder/lib/libsqlite3.so (0x00007f9945f89000)
[root@shruj01-I1850 bin]#