Hello,
I'm excited about trying Simutrans Extended -- played Simutrans years ago -- but I've hit a wall.
I'm using the Apr. 22 build on a newly installed Ubuntu 20.04.  I installed libpng12-0 following instructions found online.  When I start up the game and select either of the two Britain Paks showing (one with upper case, one with lower), the game immediately crashes with a core dump.  
jesse@anscombe:~$ /usr/local/bin/simutrans/simutrans-extended 
Parsed simuconf.tab for directory layout; multiuser = 1
Pak found: Pak128.Britain-Ex/
Segmentation fault (core dumped)
Not much information there.
I've tried the Sweden pak, too.  I get no core dump there, but I always get a map with no cities or industry.  
Any help would be greatly appreciated.  I realize that I haven't given much to go on here, but if you'll tell me how to better diagnose the problem, I'll give you more information.  Thanks much.
			
			
			
				Eh, never mind.  It seems that I should have installed both deb files and I hadn't.  It's all good now.
			
			
			
				Welcome to the International Simutrans Forum, phiwum! It's great that you managed to get Extended installed and running. Do ask if you have any questions. You might find the Quick Reference Guide for pak128.Britain-Ex (https://github.com/MatthewForrester/blends/blob/master/documentation/Quick-Reference-Pak-128-Britain-Ex.pdf) helpful.
You can also introduce yourself (https://forum.simutrans.com/index.php?topic=1354), but it's up to you.