JosefReisinger

SAD NEWS! Zoom 3.5.53922.0620, actually has stopped to work at all, as I had to notice, video connection crashes and forces the program to prompt for update, although it was patched and shows "up to date". The reason - problem with connection to server, I suppose ... so we need help from our Guru Blackwingcat - is there a possibility to get XP Version 5.0.5 (26213.0602) working with Exkernel W2k? Please, please, please!!!!

@blckwingcat Perhaps tp.dll crashes because it wants to see wireless api XP, what do you think? Greetings

Zcrashreporter produces dump files in zoom\logs. I don't have a dump viewer. But as I can see, cpthost.exe crashes with ntdll on screen sharing (old version 620). Perhaps you can have a look on it. zoomcrash.zip

Can you give advice how to solve the sceen sharing? Sorry for my impatience! Greetings

I tried to run zoom actual xp version with tp.dll 3.5.53922.620. It is not possible because of missing depends ?new_instance@socket_ctx_t@ssb@@SAPAV12@PCIIPAVmsg_db_t@2@@Z in old tp.dll. Greetings Joe

@blackwingcat: did you get my email?? Greetings

I debugged CptHost.exe with cdb.exe (old version): It seems that d3d9 is involved. d3d8thk.dll xpsp3 has function DdEntry1 ....10 in it,, d3d8thk.w2k does not, so if I use d3d8thk from XP, complaint about "missing dependency DdEntry1" in GDI32.DLL is the result. Start Screen sharing: 0:004> g Unknown exception - code 406d1388 (first chance) ModLoad: 4fd50000 4fef6000 C:\Dokumente und Einstellungen\Administrator\A ungsdaten\Zoom\bin\d3d9.dll ModLoad: 01120000 01125000 C:\WINNT\system32\d3d8thk.dll ModLoad: 768d0000 768fb000 C:\WINNT\system32\WINTRUST.dll ModLoad: 799d0000 79a56000 C:\WINNT\system32\CRYPT32.dll ModLoad: 77400000 77411000 C:\WINNT\system32\MSASN1.dll ModLoad: 76c50000 76c78000 C:\WINNT\system32\IMAGEHLP.dll If I close the app, CptHost.exe crashes: Access violation - code c0000005 (first chance) eax=00000000 ebx=00000000 ecx=00000000 edx=00000000 esi=001395f8 edi=000000 eip=7788f281 esp=0012fb68 ebp=0012fbc8 iopl=0 nv up ei pl nz na pe cs=001b ss=0023 ds=0023 es=0023 fs=0038 gs=0000 efl=000102 ntdll!RtlpWaitForCriticalSection+8a: 7788f281 ff4010 inc dword ptr [eax+0x10] ds:0023:00000010=?????? 0:000> On "Exit" in systray, Zoom.exe will not shut down. One of two instances will stay. With XP, it will close all instances. Now I need a hint of the more experienced users here: how do I find out "code 406d1388"? If I disassemble CptHost.exe, adresses are different. Greetings Joe

I disassembled CptHost.exe and got Imports and Exports. CptHostImportsExports.txt PE Explorer Disassembler found errors. *Unexpected Opcode (mov r/n16,Sreg) at 0041C200h *Line caused Error (F3 retn) at 0041BA14h The interesting entry: L00401255: mov eax,[ebp+08h] push 00000007h push [eax+04h] push [eax] call [USER32.dll!GetDesktopWindow] push eax call [USER32.dll!ChildWindowFromPointEx] L0040126C: mov edi,eax L0040126E: mov eax,edi pop edi pop esi pop ebp retn 0004h Greetings Joe

I would like to know the windows functions which are called by desktop sharing in the zoom app. Fortunally, the zoom sdk for windows is available in the net. Unfortunally, only the latest version and not v3.5. For the more advanced it should be possible to program a proper app for w2k exkernel with visual studio 2008. I found the source of screen sharing: meeting_sharing_interface.h Perhaps the more experienced users here can find out something, but I am not sure if this info is relevant. Greetings Joe

Thank you for your comment! I changed crypt32 to XP, no effect, app works but screen sharing only seems to work - conference partner only sees black screen. I think the problem could be related to graphics. In the middle of examing the graphic components, CptHost.exe will load vga.dll in XP. It will not do so in w2k exkernel. Perhaps the app needs vga service XP? I have uploaded the different outputs of procmon on w2k Exkernel and XP. Any help appreciated. Greetings Joe 2kCptHostLogfile.xls XP64CptHostLogfile.xls

Back to zoom investigation (error with black screen - screen sharing): Investigation with Pe-Explorer: CptHost.exe is loaded if video is started. If I click "share desktop", depending setupapi will load crypt32.dll, which will load msasn1.dll and wintrust.dll. Also, imagehlp.dll will be loaded. I tried to replace these with XP ones, no change. Also, changing of gdiplus will not resolve the black screen error with screen sharing. Ivestigation with procmon: zoom.exe will call msimtf, "create file mapping", and then has a lot of activities with zoomus.db in the data directory. CptHost.exe will load d3d9.dll and has a lot of registry activities checking the graphic components. So I think it will be necessary to debug CptHost.exe. Greetings Joe

Perhaps there is a problem with d3d9. If I use exkernel v3.0e d3d9.dll with zoom cloud meeting, on my system the app gets buggy, screen flickering etc. So you can copy XP d3d9.dll (I used 5.3.2600.5512, but it should also work with 5.4.21.95.5513) into the zoom folder. The app will use this one. Greetings Joe

My joy was premature - Now zoom shows desktop sharing, but the conference partners will only see a black screen instead of a presentation... :-((

Problem solved, if the proper rpcrt4.dll is used. There are two versions of exkernel rpcrt4.dll, both version 5.0.2195.7291. One has I_RpcBindingInqLocalClientPID in it, the other one not. So always use all files of Exkernel and not only replace different version numbers! Greeting Joe

Zoom cloud meetings 3.5.53922.620 will install without problems or necessary registry fakes on w2k exkernel. Download link (I had to spend some time until I found it out): https://zoom.us/client/3.5.53922.0620/ZoomInstaller.exe It will install in documents and settings\*user*\Appdata\Zoom\bin. Then we need to hexedit cmmlib.dll, XmppDll.dll, zVideoApp.dll, search for 3.5.53922.0620 and change these entries to the final version, now 4.6.19253.0401. Then the autoupdate function cannot replace the files with the newer ones which wont work. It should also be possible to install msi file with switch to diable autoupdate. The Application works, there is only one bug left: screen sharing will not work. It produces Error message 105035 "please try later". I also installed the program on Wxp32 and 64, there the screen sharing function works without error. My knowledge about screen sharing differencies between xp und 2kexkernel is not the best, perhaps some people here can help. I begged also blackwingcat with XP last version, but he did not answer. What I did yet: there are no missing dependencies of the files in this version (only mpr.dll), except cpthost.exe is missing dependeny I_RpcBindingInqLocalClientPID (known to be buggy if added in exkernel). Patching cpthost.exe with wrapper rpcXP4.dll from winxp32 has no effect, error still present. All files of zoom are digitally signed, but the signation ist not valid any more because of the time (certificate ended 2019). I consider this to be not a problem, because no other errors. Any thoughts or comments appreciated! Greetings Joe