[GNC] Deb 3.4.0.1 not working for me in ubuntu 18.04

[DaveW]

Ubuntu 18.04.  I am hoping to upgrade from GNC 3.2 to 3.4. 
 
The 3.4.0.1 Deb recently announced bombs out.  
That is to say it appears to be installing via the Software Centre. >>
Gets 100% installed. >> Offers to "Launch"(or "Remove")
Press "Launch" and it generates a "New Software Available"
message.  
Software Updater shows Gnucash available.  When run it loads
version 2.16.x Gnucash.

Need some guidance please.

Dave W