Replication task "RUN NOW" caused GUI crash.

Reporting as TrueNAS core asked me to.

After creating a replication task and pressing the "RUN NOW" button, loader apperaed and continued infinatly. Browser refresh showed the "connecting" screen but never connected.

restarting the middlewared service made the WebUI come back

Console Log output:

Mar  5 10:24:19 freenas kernel: pid 22541 (zfs), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:24:50 freenas kernel: pid 22543 (zfs), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:25:41 freenas kernel: pid 481 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:27:29 freenas kernel: pid 23162 (zfs), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:28:20 freenas kernel: pid 479 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:28:44 freenas kernel: pid 22584 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:28:50 freenas kernel: pid 22586 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:28:56 freenas kernel: pid 22591 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:29:01 freenas kernel: pid 22590 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:37:02 freenas kernel: pid 24481 (zfs), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:37:37 freenas kernel: pid 24492 (zfs), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:38:41 freenas kernel: pid 23228 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)
Mar  5 10:39:53 freenas kernel: pid 23225 (python3.8), jid 0, uid 0: exited on signal 6 (core dumped)

core files attached below

Steps to replicate:

    Not a clue.