Scribus crashes due to Signal #6

[spawes]

scribus-ng 1.5.4
Description: Linux Mint 18.3 Sylvia
Release: 18.3 64b cinnamon

When I am trying insert new footnote or move or edit existing footnote then I get "Scribus crashes due to Signal #6"
I was trying this https://bugs.launchpad.net/ubuntu/+source/scribus-ng/+bug/239227 and this https://bugs.launchpad.net/ubuntu/+source/scribus/+bug/891681 but these are not working for me.

in command line I get:
ASSERT: "pos > -1" in file /build/scribus-ng-ypYiKO/scribus-ng-1.5.4/scribus/scribusdoc.cpp, line 17505
scribus-ng: /build/scribus-ng-ypYiKO/scribus-ng-1.5.4/scribus/scribuscore.cpp:89: void abort_on_error(QtMsgType, const QMessageLogContext&, const QString&): Předpoklad „false“ nesplněn.
Scribus Crash
I am not sure if this message is useful.

Can you help please?

[Ronnie Tucker (ronnietucker)]

Also get the 'signal #6' crash when I delete a chunk of text in the Text Editor window.