Esoteric topic - installing java's old libnpjp2.so to ff-esr 52.8 on centos7 VM to access old java stuff

Folks,
I’m getting some pretty weird permissions problems trying to make this work. By my reckoning, it should be working: the horrid libnpjp2.so is linked in /usr/lib/mozilla/plugins:
image

However, ff fails to see it. After a bit of head scratching - I thought to go to the file within ff and permissions are somehow denied, but that’s not my understanding of dr-xr-xr-x:


Ditto /usr/lib64 - but, not /usr/sbin:

Which has the same permissions - excepting selinux context…:

It seems pretty obvious that if ff can’t access the directory then the plugin inside it isn’t going to work - so, ff must be intended to have permission - and, why would that have changed in the 8 or so years since is was current as I’ve just installed from an iso and upgraded to the archived repos…?

Any ideas what’s going on?
Thanks
M

selinux was restricing access, but in anycase, libnpjp2.so needs to go here ~/.mozilla/plugins/libnpjp2.so and not here /usr/lib/mozilla/plugins/libnpjp2.so