zoom cpthost.exe is using exchcsp.dll from an unknown publisher

[pepeac]

Everytime i join to a meeting I keep getting this error. "zoom cpthost.exe is using exchcsp.dll from an unknown publisher"

Can anyone Help? 

[jdott16]

Hello @pepeac 

I have seen this issue resolve by running a clean zoom which can be found at the bottom of this support article: https://support.zoom.us/hc/en-us/articles/201362163-Mass-Installation-and-Configuration-for-Windows Once that has been run head to zoom.us/download and download the 32 or 64 bit installation for your device. I hope this helps and please make sure to mark the solution as accepted if this information is what you needed.

[SandeepAgrawal]

It is happening after recent ZOOM update. Suddenly it starts appearing to multiple users. Clean un-install & install does not resolve the issue. ZOOM development team need to fix this.

[JonnyF]

I am constantly getting the following message - cpthost.exe is using GSafecsp.dll from an unknown publisher zoom message and I can't share screens on zoom so think this is related. Any fixes?

[pdarnett]

We are also having this issue and have uninstalled and re-installed several times.

[Aisling]

I am getting this error too (cpthost.exe is using exchcsp.dll from an unknown publisher) and it stops me from easily sharing my screen. I need a fix before I run my Zoom class at 09:30 BST this morning - URGENT HELP NEEDED!

[mardom005]

I have the same problem as you with sharing my screen. Did you solve the problem. Can you pls help me. 

[Tymon]

I am getting the same error (but with another dll file) - could someone help with resolving this issue?

[ejac3333]

I have the same problem  

CptHost.exe is using EXCHCSP.DLL from an unknown publisher. Are you sure you want to run this software?  It stated happening after Best Buy did an update on my computer. How do I resolve this

[MohammedOmar1B]

This also happens to me. 

[OttawaDeveloper]

I have had this issue until now. I have been getting the popup error described for some time. Today i tried to share screen and that failed, then zoom crashed.

I think i have it working for me now. 

EXCHCSP.DLL is part of Microsoft Office, i am not sure why zoom should depend on it, that is strange. 

In my case i have a very old version of Microsoft Office installed, Word 2003. It is using EXCHCSP.DLL which came with word 2003. Likely that was not properly signed or signing is out of date. 

So what i did are to rename the offending file which was here

C:\Program Files (x86)\Microsoft Office\OFFICE11\EXCHCSP.DLL

I just renamed it to EXCHCSP0.DLL

This seems to have fool the zoom stuff and it no longer connects to this DLL.

All seems good, no more popup, and share screen working.

I think zoom should look at this and see why it is depending on this file.

All this said i word seems to be still working, i hope i have not broken something in word by renaming a file that it needs.

You may need administrator rights to do this.

[danielbu]

Great! Thanks!

[adapa]

thx for drawing the connection to an old copy of Word.
I'm running a '07 version 😉

[MohammedOmar1B]

Thanks. This stops the warning. 

[Prabhuext]

We are getting the following message - cpthost.exe is using GSafecsp.dll from an unknown publisher zoom message and I can't share screens on zoom so think this is related. Any fixes?

[OttawaDeveloper]

re gsafecsp.dll or if any other DLL is named in the same way, i would begin by tracking down what that DLL is and where it came from.

This one seems to relate to some product from GemAlto, some sort of security product. I suggest you look at that, perhaps remove that product if not needed, or even do the rename trick i did, but that said it may have effects on the gemalto product. 

I did post this issue on the zoom support website also, since it sounds to me that zoom itself may be partly at fault, not sure if they will look at if there is an issue in zoom itself that causes these strange interactions.

[pdarnett]

This is the fix from Zoom support, create the following registry key and it stops Zoom scanning third party DLL's. Tested and works fine for us.

	HKEY_LOCAL_MACHINE
Key path	SOFTWARE\Policies\Zoom\Zoom Meetings\General
Value name	Disable3rdModuleVerify
Value type	REG_DWORD
Value data	0x1 (1)

[OttawaDeveloper]

That is excellent, never would have guessed that one! The fix from pdarnett of Feb 2, 2022 works for me and i was able to rename the old word DLL to its original name. Share screen works and no popup!

[rowanavita44]

I'm having the same issue also with the CPT. message. It even affected Screen Sharing. This is so frustrating. It started occurring when I did the latest Zoom update.   GRRRRR!!!!!!

[pdarnett]

Did you try this?

This is the fix from Zoom support, create the following registry key and it stops Zoom scanning third party DLL's. Tested and works fine for us.

	HKEY_LOCAL_MACHINE
Key path	SOFTWARE\Policies\Zoom\Zoom Meetings\General
Value name	Disable3rdModuleVerify
Value type	REG_DWORD
Value data	0x1 (1)

[Alcrisp]

Thanks for sharing your fix! This error just started showing up for me with the last Zoom update, so Zoom needs to figure it out on their end. What I've always heard is that you aren't supposed to mess with the registry if you don't know what you are doing. Seems like it is an ongoing problem and users shouldn't need to find a work around. 😛

Meanwhile, I am wondering if you can provide more information/detailed steps for those of us who aren't tech people? I don't know what I am supposed to do with that information. Thanks!

[RN]

Hey @pepeac it's been some time since you've posted your discussion and you have some great replies here!

If any of these replies within your discussion answer your issue don't forget to click the accept as solution button next to a reply!