I updated my Ubuntu and now get an error as follows:

$ ./okcash
./okcash: error while loading shared libraries: libboost_system.so.1.58.0: cannot open shared object file: No such file or directory

Looking up libboost_system.so*, I see that i have
/usr/lib/libboost_system.so.1.61.0

Should i re-install the wallet?

Does the mining/staking of OKCash only require that our client/wallet is connected to the network and there is no actual PoW process that happens after the PoS?
Somebody please just explain the tech behind how the staking happens and blocks are added to the OKCash blockchain.