[ISSUE] Graph Explorer fails to load

[nekineznanec]

When opening the Dashboard on Graph Explorer, the page fails to load and I get the following error:

An error occurred.
          Error: Network error: Unexpected token < in JSON at position 0
    at new ApolloError (/graph-explorer/node_modules/apollo-client/bundle.umd.js:59:32)
    at QueryManager.<anonymous> (/graph-explorer/node_modules/apollo-client/bundle.umd.js:1183:49)
    at step (/graph-explorer/node_modules/tslib/tslib.js:133:27)
    at Object.next (/graph-explorer/node_modules/tslib/tslib.js:114:57)
    at /graph-explorer/node_modules/tslib/tslib.js:107:75
    at new Promise (<anonymous>)
    at Object.__awaiter (/graph-explorer/node_modules/tslib/tslib.js:103:16)
    at /graph-explorer/node_modules/apollo-client/bundle.umd.js:1146:87
    at /graph-explorer/node_modules/apollo-client/bundle.umd.js:1626:21
    at Array.forEach (<anonymous>)