yup, I have the same problem.

CONFIG:Loading settings from config file /usr/local/dosbox/etc/dosbox.conf
ALSA lib seq_hw.c:446:(snd_seq_hw_open) open /dev/snd/seq failed: No such file or directory
ALSA:Can't open sequencer
MIDI:Opened device:none

My sound card alsa module is es1371 (ac97),
using Mandrake 9.2, kernel 2.4.22-10mdk.

Could anybody please help us about this problem?
Thanks a lot!

you need to load the sequencer modules, snd_seq, snd_seq_midi, snd_seq_oss. This ought to fix the problem.

For me, it just changes the error message to
ALSA:Can't subscribe to MIDI port (65:0)
MIDI:Opened device:none

Does this help? Can anyone help with my problem?

whoops forgot to mention, cpu athlon 64 3000+
linux 2.6.6 in 64 bit mode, running a 32bit compile of dos box.
Gigabyte k8n Pro motherboard, Nforce3 chipset
1 gig ddr 400 ram
Nforce 3 integrated audio using the alsa drivers, not the nvidia ones
dosbox .61
I have tried default alsa and oss for the mpu401 device= option
Native 64 bit compiles segfault, *after* giving the same midi error. Here is a back trace from this segfault
#0 0x0000000000456bd0 in void Normal<8, 32, false>(unsigned char*) ()
#1 0x000000000044ce42 in VGA_DrawPart() ()
#2 0x0000000000448cce in PIC_RunQueue() ()
#3 0x0000000000406049 in Normal_Loop() ()
#4 0x000000000040611a in DOSBOX_RunMachine() ()
#5 0x0000000000406de6 in CALLBACK_Idle() ()
#6 0x0000000000461139 in INT16_Handler() ()
#7 0x000000000040608f in Normal_Loop() ()
#8 0x000000000040611a in DOSBOX_RunMachine() ()
#9 0x0000000000406faf in CALLBACK_RunRealInt(unsigned char) ()
#10 0x000000000042e5c6 in device_CON::Read(unsigned char*, unsigned short*) ()
#11 0x0000000000430688 in DOS_ReadFile(unsigned short, unsigned char*, unsigned short*) ()
#12 0x000000000046b81b in DOS_Shell::InputCommand(char*) ()
#13 0x0000000000467e9f in DOS_Shell::Run() ()
#14 0x0000000000468b27 in SHELL_Init() ()
#15 0x0000000000464d97 in Config::StartUp() ()
#16 0x0000000000455143 in main ()

You need to specify your alsa port, unless it is not 65:0. Here is snip from my dosbox.conf:

device=alsa
config=64:0

thanks that was half of the problem, the other half is that my audio drivers didn't provide midi support. *doh* Configuring timidity to handle midi worked.

I've got some kind of same problem, my error message follows:
CONFIG: Using default settings. Create a configfile to change them
Xlib: extension "XFree86-DRI" missing on display ":0.0".
Fatal signal: Segmentation Fault (SDL Parachute Deployed)

But nothing else, I'm not sure for me it is a sound Problem...
Could you help me ?

DRI is for direct rendering on Linux. My first thought would be to make sure that you have the 3d running. At a console (or terminal) when running X windows, type glxinfo and at the very start where it says Direct Rendering see if it says yes. If it does I can't help.

You could also check the /var/logs/XFree86.0.log to see what it says about the XFree86-DRI, direct rendering, and drm. (Personally I've had trouble sometimes with getting the 3d running and usually it's had something do with agpgart(dealing with agp support))
It might not hurt to look at the results from dmesg and also /var/log/messages (the last one you'll have to look at as root).

name of display: :0.0 Xlib: extension "XFree86-DRI" missing on display ":0.0". display: :0 screen: 0 direct rendering: No ... […]
Show full quote

name of display: :0.0
Xlib: extension "XFree86-DRI" missing on display ":0.0".
display: :0 screen: 0
direct rendering: No
...

How make to run direct rendering?

First a disclaimer if you're using a NVIDIA card or any other using proprietary drivers for other cards I likely won't be able to help you.

About getting the XFree86-DRI to load you're going to have to find out why it isn't loading. As I said above (for some reason I wasn't logged in even though I was) you should try checking out the /var/log/messages and /var/log/XFree86.0.log paying attention for dri and running dmesg to look for other messages wouldn't hurt. Without more details I can't help.

And it wouldn't hurt to try running your error messages through Google you're likely to get an answer much faster and in more detail than from here.