Error: Can't set headers after they are sent.
at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:356:11)
at sendSPA (/usr/src/app/server/router.js:293:9)
at /usr/src/app/server/router.js:187:14
at /usr/src/app/server/router.js:266:11
at done (/usr/src/app/server/dats.js:56:12)
at /usr/src/app/server/dats.js:75:36
at /usr/src/app/node_modules/hyperdrive/index.js:514:55
at onnodes (/usr/src/app/node_modules/append-tree/index.js:116:33)
at onget (/usr/src/app/node_modules/append-tree/index.js:348:21)
at _combinedTickCallback (internal/process/next_tick.js:77:11)
at process._tickCallback (internal/process/next_tick.js:98:9)