Blue Iris won't load after Windows 11 update March 2026 - avnetsdk err 126

C

Cow_Stretcher

n3wb
Aug 10, 2025
5
0
USA
Hi,
Blue Iris was working fine on 5 cameras before a Windows 11 update recently. After the update BI launches briefly but wont load the full app and in Task Manager shows it suspends and closes. No main log file is being created.
Error from sdk_log:AVNetSDKMgr.cpp:658 — Test load avnetsdk err 126

I've already tried:
  • Reinstalled all Visual C++ runtimes using VisualCppRedist_AIO_x86_x64
  • Fresh reinstall of Blue Iris to C: drive
  • Checked Windows Defender quarantine — nothing there
  • avnetsdk.dll cannot be found anywhere on my system

BI is installed on C:, data/clips are in C:\BlueIris. Running Windows 11, 5 Dahua cameras.
Any help appreciated!
 
I did a quick search of the internet and there is some indication that avnetsdk.dll may be part of some software from Dahua, do you have some software called Patriot on your computer by any chance

I also found a reference to that file in this thread
A

Thread 'Dahua SmartPSS Crashing in Windows 10'

I am constantly getting intermittent crashes of SmartPSS in Windows 10 x64 on several PCs.
Have updated to latest windows updates and makes no difference.(was crashing prior to updates)
I have tried several laptops and desktops and seems not very reliable at all to use for constant viewing.
A bit disappointing considering i spent some money on Dahua cameras 2 x IPC-HFW1831E (latest firmware) and Dahua Nvr ->Dahua NVR4108-8P-4KS2 (latest firmware from this here)

I have SmartPSS downloaded and installed from Dahua Wiki (SmartPSS 2.02.7)

Anyone have SmartPSS running reliably without the...
Click to expand...
I did find the file on my BI 6 system in a folder "C:\Program Files (x86)\ConfigTool\ConfigTool", ConfigTools is for Dahua Camera setup!
Hope this helps!
 
Bruce_H said:
I did a quick search of the internet and there is some indication that avnetsdk.dll may be part of some software from Dahua, do you have some software called Patriot on your computer by any chance

I also found a reference to that file in this thread

I did find the file on my BI 6 system in a folder "C:\Program Files (x86)\ConfigTool\ConfigTool", ConfigTools is for Dahua Camera setup!
Hope this helps!
Click to expand...
I'm using the empiretech cameras which are just like them i think, in that post i saw it and it said they were having problems before the update but mine were fine before, so i didn't read much into it.
I used Claude AI to try and trouble shoot this and it actually told me to come here and post after trial and no success!LOL "the BI developer Ken actually responds there and this is exactly the kind of thing he can fix in one reply."

Claude explained it was also with the dahua and said "That DLL needs to come from the Dahua SDK package that Blue Iris bundles" and it has come up missing somehow.

I don't have the patriot software installed.
Also checked for configtool and I dont have that folder under C:\Program Files (x86)\ConfigTool\ConfigTool
 
Well, It is strange because the only place that the avnetsdk.dll exists on both of my BI system is in the location C:\Program Files (x86)\ConfigTool\ConfigTool, if you set up your Dahua cameras did you not use the Dahua ConfigTool. perhaps you could try installing it on your BI PC to see if it resolves the error! On both of my BI systems I have the ConfigTool installed, but in both cases BI was up and running before that software was installed, if it came bundles with BI you would think that it would exist in the BI folder structure. Another thought would be to open an admin cmd prompt and run this command "SFC /scannow" that will check all of your windows files and fix any possible windows file errors, no risk in trying it!
 
Bruce_H said:
Well, It is strange because the only place that the avnetsdk.dll exists on both of my BI system is in the location C:\Program Files (x86)\ConfigTool\ConfigTool, if you set up your Dahua cameras did you not use the Dahua ConfigTool. perhaps you could try installing it on your BI PC to see if it resolves the error! On both of my BI systems I have the ConfigTool installed, but in both cases BI was up and running before that software was installed, if it came bundles with BI you would think that it would exist in the BI folder structure. Another thought would be to open an admin cmd prompt and run this command "SFC /scannow" that will check all of your windows files and fix any possible windows file errors, no risk in trying it!
Click to expand...
I didn't need the config tool to set them up, i just went straight into the IP and configured the cams off that. Also ran SFC /scannow with no luck.
I d/led the config tool and then transferred the files below over to C:\Program Files\Blue Iris and that helped but the error just changed from 126 to 193 — that means it's now FINDING the avnetsdk.dll file but can't load it. Error 193 means "not a valid Win32 application" — in plain English, the DLL you copied is 32-bit but Blue Iris needs a 64-bit version.
  • dhnetsdk.dll
  • dhconfigsdk.dll
  • avnetsdk.dll
 
Well I would say that it's time to email support if you have a current support contract, need to use the info in "Settings", "Get Support" or your email will not get past their spam filters!
 
Bruce_H said:
Well I would say that it's time to email support if you have a current support contract, need to use the info in "Settings", "Get Support" or your email will not get past their spam filters!
Click to expand...
I do still have the support, i just thought here would be faster, last time i emailed them it took 5 days to respond. I just sent one over to them, Thank you for the help!
 
Cow_Stretcher said:
I'm using the empiretech cameras which are just like them i think, in that post i saw it and it said they were having problems before the update but mine were fine before, so i didn't read much into it.
I used Claude AI to try and trouble shoot this and it actually told me to come here and post after trial and no success!LOL "the BI developer Ken actually responds there and this is exactly the kind of thing he can fix in one reply."

Claude explained it was also with the dahua and said "That DLL needs to come from the Dahua SDK package that Blue Iris bundles" and it has come up missing somehow.

I don't have the patriot software installed.
Also checked for configtool and I dont have that folder under C:\Program Files (x86)\ConfigTool\ConfigTool
Click to expand...

And to show that AI isn't always right, Ken the BI developer is not on this site!

Most of us here don't use the ConfigTool, so that isn't how our system obtained that file.
 
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wittaj said:
And to show that AI isn't always right, Ken the BI developer is not on this site!

Most of us here don't use the ConfigTool, so that isn't how our system obtained that file.
Click to expand...
Yeah, I was skeptical about that one for sure, I generally us AI for help with coding and simple trouble shooting and its worked ok for my knowledge level. After speaking with support I had to do a complete reinstall and I'm able to bring up the console now but the previous backup corrupts the system again. So it's back up and working which is awesome but hopefully I can get the backup fixed.
 
wittaj said:
And to show that AI isn't always right, Ken the BI developer is not on this site!

Most of us here don't use the ConfigTool, so that isn't how our system obtained that file.
Click to expand...
@wittaj you say that your BI system has never had the ConfigTool installed, if that is the case where is the avnetsdk.dll located on your system? Just curious!
 
wittaj said:
That is what it seems like, but that wouldn't explain the error the OP got as it relates to starting BI, unless it is in the newest version?
Click to expand...
Both of my systems are running BI 6.0.4.2, which is the most recent release, and the file does not exist in the BI folders, only in the ConfigTool from Dahua, I guess I could remove the ConfigTool and see if it causes BI any issues!
 
Bruce_H said:
Both of my systems are running BI 6.0.4.2, which is the most recent release, and the file does not exist in the BI folders, only in the ConfigTool from Dahua, I guess I could remove the ConfigTool and see if it causes BI any issues!
Click to expand...
As expected after I removed the ConfigTool, the file avnetsdk.dll, no longer exists and Bi is working normally! Interestingly I looked at the sdk_log.log in the "C:\Program Files\Blue Iris\sdk_log" and I have this same error and it has no effect on my BI program; here is the line that is in the sdk_log.log file on my system "[2026-03-17T23:45:01.502 info Netsdk:41296 8056:2356 AVNetSDKMgr.cpp:658]Test load avnetsdk err 126", I am begining to suspect that this entry is not the cause of the problem reported by @Cow_Stretcher !
 
Cow_Stretcher said:
Hi,
Blue Iris was working fine on 5 cameras before a Windows 11 update recently. After the update BI launches briefly but wont load the full app and in Task Manager shows it suspends and closes. No main log file is being created.
Error from sdk_log:AVNetSDKMgr.cpp:658 — Test load avnetsdk err 126

I've already tried:
  • Reinstalled all Visual C++ runtimes using VisualCppRedist_AIO_x86_x64
  • Fresh reinstall of Blue Iris to C: drive
  • Checked Windows Defender quarantine — nothing there
  • avnetsdk.dll cannot be found anywhere on my system

BI is installed on C:, data/clips are in C:\BlueIris. Running Windows 11, 5 Dahua cameras.
Any help appreciated!
Click to expand...

Most of my systems are running Blue Iris 6.0.4.2 on Windows 11 25H2. None of them have a file containing the name avnetsdk present, and they all print a set of lines like this to the sdk_log.log file when opening the Blue Iris GUI:
Code: 
Begin Time:2026-03-17T23:39:09.158
[2026-03-17T23:39:09.158 info Netsdk:41296 7964:8168 Utils.cpp:4815]mutil NIC client
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 AVNetSDKMgr.cpp:658]Test load avnetsdk err 126
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:159]Leave CLIENT_InitEx.
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:190]Enter CLIENT_SetAutoReconnect:[cbAutoConnect=000000014069BD50, dwUser=0000000003516AB0].
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:192]Leave CLIENT_SetAutoReconnect.
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:389]Enter CLIENT_SetDVRMessCallBack: [cbMessage=000000014069BC20, dwUser=0000000003516AB0].
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:391]Leave CLIENT_SetDVRMessCallBack.
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:6911]Enter CLIENT_GetLastError.
[2026-03-17T23:39:09.159 info Netsdk:41296 7964:8168 dhnetsdk.cpp:6914]Leave CLIENT_GetLastError.[Error code=0.]

I have log files from Blue Iris 5 with these (almost exact) messages dating back as far as October 2020 (might have had earlier instances, but they were wiped when upgrading to Blue Iris 6). One PC created a file next to it named 1_sdk_log.log, a whopping 10 MB large with older entries than the sdk_log.log file. Windows error code 126 maps to the message "The specified module could not be found."

Anyway, I ran into a similar problem last summer, where Blue Iris abruptly wouldn't load and gave absolutely no indication of why it was immediately exiting/crashing when the service was started or the GUI opened, and traced it back to some weird dependency on the legacy Msfs stub driver. I am not aware of any other software that needs it in order to operate, but you could check to make sure it's working on your system by downloading System Informer, heading over to the Services tab, scrolling down to find Msfs, and verifying that line shows Msfs, FS driver, Running, System start. If it's not running or not present, it's possible it got broken in the Windows Update.
 
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