Someone brought this up like a year ago, but I figure I should reiterate: trying to run the launcher in Gentoo Linux produces the error,
./Launcher: /usr/lib64/libssl.so.1.0.0: version `OPENSSL_1.0.1' not found (required by ./Launcher)
./Launcher: /usr/lib64/libssl.so.1.0.0: version `OPENSSL_1.0.0' not found (required by ./Launcher)
./Launcher: /usr/lib64/libcrypto.so.1.0.0: version `OPENSSL_1.0.2' not found (required by ./Launcher)
./Launcher: /usr/lib64/libcrypto.so.1.0.0: version `OPENSSL_1.0.0' not found (required by ./Launcher)
This seems to relate to patching that Ubuntu did to OpenSSL, which then got inherited into the Linux build process for Last Epoch. But since OpenSSL is, of course, open-source, it seems to me that a simple solution would be to ship the libcrypto.so and libssl.so files used for linking along with the Linux launcher—or an even simpler solution (which I think is fine with OpenSSL’s license) would be, statically linking the game against OpenSSL. It’s not like that would bloat the binaries or anything.
Anyway, I managed to fix the problem (by getting the .so files distributed by Ubuntu and overriding LD_LIBRARY_PATH) but it was a bit of a wild ride.