Hi all,
Posting this in case anyone has ever had this problem before. I am running a fairly fresh install of Ubuntu 20.04 on my Dell laptop.
Up until a few days ago, everything was working fine. I was emulating the old PC game Where In Europe is Carmen Sandiego without any issues.
I've not changed anything to any config files, but I've installed the usual system updates whenever prompted. Something has now caused this issue, as whenever I start Dosbox, I get this message:

1DOSBox version 0.74-3
2Copyright 2002-2019 DOSBox Team, published under GNU GPL.
3---
4CONFIG:Loading primary settings from config file /home/jrong/.dosbox/dosbox-0.74-3.conf
5MIXER:Got different values from SDL: freq 44100, blocksize 512
6ALSA:Can't subscribe to MIDI port (65:0) nor (17:0)
7MIDI:Opened device:none

Now the sound no longer works when I am running the game. Anyone know what I can do about this?

If I edit the dosbox-0.74-3.conf file and change the blocksize (under mixer settings) to 512, I get the same error message as above, except that the blocksize value is now 256.
I don't know much about Midi or audio settings but I would really like to get my sound working again - so thanks if anyone can help?

Arte