Soo, there appeared to be two errors. One with the nginx config which I solved in the past ( a / typo behind the proxy_pass ) for anyone having this same issue make sure you double check the nginx rules for a typo.
Did editing of the package.json file
went to node_modules;
make installation of 0.3.0 which was offered by npm;
upgrade button appeared on the db-search plugin;
made upgrade trough admin panel;