What version are you trying to install? I am getting (presumably) the same error when trying to install 1.10 or 1.00 either from wireshark or from the npcap installer on Windows 10.

I don't think, npcap is running, but I could be mistaken.

I'm experiencing the same issues ever since attempting to upgrade from 1.00 to 1.10. Now I cannot even install 0.9991.
0.99-r7 installs without errors.

Related:
#104
#286

I solved it for myself. If anyone else experiences this issue and is working remotely via citrix, not using citrix (directly) might help solve it for you.
You'll want the connection to your PC to run via remote desktop, not citrix. If your Citrix Receiver allows for it, establish a connection to a general desktop and then connect via remote desktop to your machine from there.

I was able to reproduce this issue. Worked fine via RDP, failed with error 255 when connected via Citrix.

I've run into this issue as well, and I can confirm @urbanhusky's workaround works:

• Installing through Citrix Receiver connection: fails.
• Installing through Remote Desktop connection: success!

I feel like this is probably more of a Citrix issue than an npcap issue, but it would be nice if things "just worked." 😄 I see there's an issue already about updating the version of the NSIS installer being used (#292) - maybe newer versions of the installer address this particular issue?

@9numbernine9 Thanks for confirming the issue. Npcap 1.20 uses NSIS 3, so we would appreciate if someone could answer whether the issue is resolved or persists there. Additionally, if someone could verify the size and digital signature of the SimpleSC.dll that is present but not loaded, that could inform us whether there is a corruption of the file as it is unpacked. Does Citrix enforce a storage quota that our installer might be exceeding?

@dmiller-nmap Sorry for taking so long to respond!

I tried again today with the NMAP 1.20 installer, but it seems to have the same behaviour as before. The error code is Runtime error at 773C9862 - not the exact same error code as before, but I suspect it's the same problem.

Looking in the temporary directory that the installer creates (C:\Users\myname\AppData\Local\Temp\randomstring.tmp\), the following files were extracted, along with their size and the first part of the SHA256 hash:

As before, using Remote Desktop Connection instead of Citrix lets the installation work perfectly. I wish I knew enough about Citrix to offer more suggestions but alas. 😞

@dmiller-nmap I can confirm @9numbernine9 's findings. The device hosted over Citrix Remote Access is the trigger. Works fine on the same device when just done over RDP (or physical console). As to storage quotas or any user profile management items that Citrix provides, those are not in play for my situation. They are not present or not turned on.

At this point, I'm going to test telling Citrix not to hook and see if it makes a difference or not.

@dmiller-nmap It is the Citrix hooking that causes the issue. When I exclude NPFInstall.exe, the problem does not happen. When I get another chance, I'll try and see if I can at least narrow it down to which hook is causing the issue as that might shed some light on the npcap side to fix it.

Can anyone confirm whether the disk location of the installer in this case is local to the machine being installed or is accessed remotely? We're pretty sure that nmap/npcap-build@61cc998659bf5f16711bc4a27f1f14c3a0a15516 will fix the issue, but we would like to investigate whether a potential workaround would be copying the installer to the target machine before running it.

I found no difference in behavior when running it locally vs remote, interactive or silent.

As info, for the Citrix hooking DLL part of this, the installer still throws the error and prevents continuing through the install. While some parts of this issue may be resolved with 1.50, the core reported issue has not.

I can confirm that NPCAP is still exhibiting this error using Npcap 1.50 installer over citrix. Same error, using a local disk as the origin of the installer. I can also confirm that disabling hooking also did the trick as a temporary workaround for me.

For reference/information, I had to include the installer file in the ctx hooks (e.g. npcap-1.50.exe), only NPFInstall.exe did not turn out to be sufficient for me. This is the reg file I used:

[HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\CtxHook]
"ExcludedImageNames"="NPFInstall.exe,npcap-1.50.exe"

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Citrix\CtxHook]
"ExcludedImageNames"="NPFInstall.exe,npcap-1.50.exe"

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Citrix\CtxHook64]
"ExcludedImageNames"="NPFInstall.exe,npcap-1.50.exe"

The changes in 1.60 fix the issue with Citrix.

The changes in 1.60 fix the issue with Citrix.

Can yur tell me how to fix? I met the same error in my installer(make by inno setup). Thanks!

Experiencing the same 255 error. Based on @urbanhusky report I tried to login via RDP but admin has disallowed login with RDP. So instead, as I was logged in with Citrix, I started the installation, after the options where made and the installation was on its way, I disconnected from Citrix. And it worked. Shoutout to @urbanhusky