installing minimserver on netgear R7000 router flashed with advanced tomato firmware

[simoncn]

Have you verified that the /opt/java/jdk1.8.0_121/bin/java file exists?

If so, this message can mean that there has been a problem loading shared libraries required by the java executable. You can use the command

ldd -v /opt/java/jdk1.8.0_121/bin/java

to get more information about this. Please post the output from this command here.