My apps fail with a 500 error

Error: Client request error: socket hang up
   at createHangUpError (_http_client.js:342:15)
   at Socket.socketOnEnd (_http_client.js:437:23)
   at emitNone (events.js:111:20)
   at Socket.emit (events.js:208:7)
   at endReadableNT (_stream_readable.js:1064:12)
   at _combinedTickCallback (internal/process/next_tick.js:139:11)
   at process._tickDomainCallback (internal/process/next_tick.js:219:9)

Is there anything one can do to clear this error?
It seems to appear as soon as I add some secrets to an app.