Gnucash 2.6.18 crashes in MacOS 10.13.1 High sierra

[martin kirby-sykes]

I have been using Gnucash under Linux for many years but recently
transferred to a MacBook 6.1 running High Sierra.

When I try to post a transaction the screen goes black.  The menu bar
remains available but inactive.  I have to close Gnucash down by forcing it
to quit in Activity Monitor.

Anyone have similar experience or clues about how to proceed?

Many thanks

Martin