DeviceHostWindows.exe Crashing PC

[andrewj]

Hi All. I think I'm slowly peeling back multiple layers of issues here.

Channels now refreshed from scratch. All names look sensible and I know they are all currently available on my tuner. Apologies if I didn't understand the "copy" instruction first time round, but it worked for the secondary tuners.

I didn't get anything auto-mapped to SD, but I manually set all the channels I'm interested in. Doing the channel refresh and building the SD list from scratch has cleared an odd warning I was getting with the SD update, so that's all clean now.

I'm beginning to suspect that the crashes are due to faulty tuner hardware. After it crashed yesterday I unplugged Tuner 2 and noticed it was running a bit hot. Let's see if that improves the system stability.

Re channel sorting, this did work in the old version of the client, but it may have been an unintended and undocumented feature!   It might be one to put on the future improvements list. In the UK the channels of most interest (e.g. BBC1 HD) are all on channels with numbers above 100, so they are low down in the EPG compared with a lot I use less frequently. The ability to put them at the top (which did work, even if unintentionally) was great.

Thanks for all the help. I'll let you know if this has stabilised things.

[jimil]

sorting, this did work in the old version of the client, but it may have been an unintended and undocumented feature!   It might be one to put on the future improvements list. In the UK the channels of most interest (e.g. BBC1 HD) are all on channels with numbers above 100, so they are low down in the EPG compared with a lot I use less frequently. The ability to put them at the top (which did work, even if unintentionally) was great.

You can still sort the channels in any order you wish.
 If you go to Settings/Channels (Web App) you can set the order the channels display in by using the spanner icon to Edit Channel Details. 
By changing the number you can put the channels in any order you want (you can also rename then here) changing the channel order (or channel names) here also changes the channel order (or names) in any groups that the channel is or that you create.  It's a little clunky (drag/drop would be easier) especially if you have a lot of channels but it does work, previous version was the same. When I first set up NPVR about 18 months ago I used this method to put the channels in the same order as on my Topfield PVR

[mvallevand]

To clarify something I said earlier I did some testing with <SortChannelGroups> and I was wrong about how it works, it doesn't turn off sorting sorting in groups, it defines the order that groups are display. So you can get delete all your groups set the sort to false and maybe put your favourites in one group, add another for the channels over 100 you faster navigation. Switching groups is pretty fast in NextPVR.exe and UI cliients, Kodi etc.

Martin

[andrewj]

Hi All,
I've managed to stabilise my system, as follows:

• Moved recording to another PC. This is working fine, using the same Hauppage tuners & settings. One thing to note is that this system has only ever had NPVR 7.0 installed, and I made sure to only install the latest Hauppage drivers.
  
• Stopped and disabled NPVR on the original system
  
• Deleted the old tuner devices and their drivers. I had to do this twice until plugging one in got a "driver needed" alert
  
• Manually deleted C:\Windows\System32\Drivers\EMBDA64.sys, which was consistently reported as the faulting module in the crashes. That hasn't caused any problems, so it was only being used by the tuners
  

Noting that the problems on the original system persisted when I unplugged the tuners in turn, and that the problems haven't manifested on the other system, means it doesn't look like a tuner hardware fault.

Now I completely get what sub is saying about managed vs kernel code, and I'm not directly blaming NPVR, but it's clear that the "TV recording activity" was causing the problems. It might be worth reviewing whether we can get any clues to the underlying issue from the various logs and dumps.

I would like to return recording to the original system, but at the moment I can't afford to destabilise it again. I'm also waiting to see if recording on the other system has the same problem of intermittent glitches in the recordings, which has been a long-running nuisance on the main system.

When I do so I plan to:

• Completely delete NPVR
  
• Reboot and delete the NPVR data directories (I have the recordings etc. on the other system)
  
• Re-install NVPR 7.0
  
• Re-install the tuners with the new drivers
  
• Set up from scratch, copying recordings etc. across from the other system
  

Can anyone think of anything else I need to do?
Thanks, Andrew

[mvallevand]

You both are right. There is an issue with NextPVR that triggers the error. It is modifying an API call that it shouldn't which is not a good situation but the API should be able to prevent this but it is not so the API itself triggers the crash.

Basically I suggest you try this binary https://forums.nextpvr.com/showthread.ph...#pid596444 and see how it works for you. It should prevent many crashes.

Martin

[andrewj]

Thanks Martin. That all makes sense, and hopefully if it's a known problem at some point sub will find a permanent fix. I'll make a donation!

I think I'll leave it for a couple of weeks (I need my systems to be stable while I'm having some medical treatment), and then I'll make restoring NPVR part of the planned Windows 11 rebuild. We may find that with a fresh install it works OK (as it has on the other hardware), but if not I'll try your fix, and let you know.
Thanks again.

[jobby99]

Thanks Martin. That all makes sense, and hopefully if it's a known problem at some point sub will find a permanent fix. I'll make a donation!

I think I'll leave it for a couple of weeks (I need my systems to be stable while I'm having some medical treatment), and then I'll make restoring NPVR part of the planned Windows 11 rebuild. We may find that with a fresh install it works OK (as it has on the other hardware), but if not I'll try your fix, and let you know.
Thanks again.

Does anyone have any kind of definitive diagnosis as to how the hardware (possible overheat)/driver (old/corrupted) interfaces with poor signal (probably symbol quality) to kill nextpvr service and/or produce windows errors?  I am trying to diagnose something myself and believe it has to do with weak antenna signals that cause some sort of cascading effect ultimately shutting down nextpvr service from windows runtime error.  To test, I am going to run system with only known high quality channels (all 75% and up in the green) to see if the same problem occurs or if it happens much less frequent.  I almost think these hard to define problems with the tuner deserve their own forum section.

[mvallevand]

@jobby 99 This DVB OTA scan issue isn't directly related to your post so probably best not to hijack this thread. You also need to post logs closer to when a problem occurs. I didn't see a tuner crash going back to the 25th.

Martin