Just recently I've been getting problems with Kstars crashing on the splash screen - just after it gets to 100% on loading NGC/IC Objects.

Not really sure where to start but I ran it in gdb and got:
(gdb) run
Starting program: /usr/bin/kstars
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe2ba1700 (LWP 7558)]
[New Thread 0x7fffd8f83700 (LWP 7559)]
[New Thread 0x7fffd3fff700 (LWP 7560)]
[New Thread 0x7fffd37fe700 (LWP 7561)]
[New Thread 0x7fffd0a41700 (LWP 7563)]
[New Thread 0x7fffc3fff700 (LWP 7564)]
[New Thread 0x7fffc1c15700 (LWP 7565)]
[Thread 0x7fffd0a41700 (LWP 7563) exited]

Thread 1 "kstars" received signal SIGSEGV, Segmentation fault.
0x00007ffff3ba170f in QString::operator=(QString const&) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
(gdb)

Indi itself seems to be working - e.g. I can connect to devices through PHD2

Happy to provide any information needed - just need some guidance what to do next to debug

type in bt right there to get the backtrace. Also, are you compiling from GIT or using the PPA?

I'm using the PPA. Ubuntu 16.04 AMD64
(gdb) bt
#0 0x00007ffff3ba170f in QString::operator=(QString const&) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#1 0x000000000090c1dc in ?? ()
#2 0x000000000090cbdc in ?? ()
#3 0x000000000090b681 in ?? ()
#4 0x000000000073dab9 in ?? ()
#5 0x000000000070e8d3 in ?? ()
#6 0x00000000004ae82e in ?? ()
#7 0x00000000004d4c2f in ?? ()
#8 0x00000000004d5039 in ?? ()
#9 0x00000000004834a1 in ?? ()
#10 0x00007ffff25e3830 in __libc_start_main (main=0x481b30, argc=1,
argv=0x7fffffffded8, init=<optimised out>, fini=<optimised out>,
rtld_fini=<optimised out>, stack_end=0x7fffffffdec8)
at ../csu/libc-start.c:291
#11 0x0000000000490129 in _start ()
(gdb)

Doesn't look like a KStars problem, something botched in your installation. Try doing a 'sudo apt-get update && sudo apt-get -y dist-upgrade'

I've had Indi/kstars/EKOS running reliably for some time. During some recent regular software updates I did see some errors.
I tried the above but no joy. So I then did:
sudo apt-get remove kstars-bleeding
sudo apt-get remove indi-full
sudo apt autoremove
sudo apt-get install indi-full kstars-bleeding

to get a full reinstall but still no luck.
Is it possibly a corrupted file in the kstars cache? Should I try clearing out ~/.local/share/kstars or similar?

I renamed the kstars folder under ~/.local/share to kstars-old and also renamed knewstuff3 to knewstuff3.old
Then I launched kstars and it worked, creating a new kstars folder in the process.
Also check back through all the log files and found that on 31-Oct it was stopping when reading supernovae.dat. Prior to that it did lots more.
So I restored the old kstars folder but renamed supernaovae.dat to supernovae.dat.old
Launched kstars and all is good now.
Now to sort out some indi issues on my raspberry pi but that another story.

EDIT: Just compared the two versions of supernovae.dat and it was indeed corrupted.. Instead of 2015ac it reads <a name,"2015a and ends there