Crashing 1.6.21 / Debian stretch

On Debian Stretch up to date, I just installed new version of Duniter 1.6.21

It's completely instable for me, here is a crash log:

2018-03-04T16:44:55+01:00 - error: Error [ERR_IPC_CHANNEL_CLOSED]: Channel closed at ChildProcess.target.send (internal/child_process.js:606:16) at Worker.send (internal/cluster/worker.js:40:28) at PowWorker.sendCancel (/opt/duniter/app/modules/prover/lib/PowWorker.js:76:27) at slaves.forEach.s (/opt/duniter/app/modules/prover/lib/powCluster.js:116:22) at Array.forEach (<anonymous>) at Master.cancelWorkersWork (/opt/duniter/app/modules/prover/lib/powCluster.js:115:21) at Master.cancelWork (/opt/duniter/app/modules/prover/lib/powCluster.js:125:14) at PowEngine.cancel (/opt/duniter/app/modules/prover/lib/engine.js:43:29) at WorkerFarm.stopPoW (/opt/duniter/app/modules/prover/lib/blockProver.js:70:53) at BlockProver.cancel (/opt/duniter/app/modules/prover/lib/blockProver.js:122:24) at <anonymous> at process._tickCallback (internal/process/next_tick.js:160:7)