# Cannot connect to Catalyst Live visualization on Mac OS X
**URL:** https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301
**Category:** ParaView Support
**Created:** [July 11, 2018, 3:27pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301 "2018-07-11T15:27:20Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Senui](https://discourse.paraview.org/u/Senui)
#### Post date: [July 11, 2018, 3:27pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/1 "2018-07-11T15:27:20Z")
Hello,
I am trying to get a simple live visualization demo to run on Mac OS X 10.11. It’s the `CxxNonOverlappingAMRExample`. I am using ParaView v5.5.2. By the way, the example runs fine on my Linux machine.
The steps to reproduce the issue:
1. In the `CxxNonOverlappingAMRExample` there is a Python pipeline, where I set the `EnableLiveVisualization` option to `true`.
2. Build the example
3. Open ParaView and connect to Catalyst on port 22222 (same as in the Python pipeline)
4. Execute the example as such: `./CxxNonOverlappingAMRExample ../SampleScripts/feslicescript.py`.
What I get in return is the following error message:
```auto
ERROR: In /Users/senui/paraview/VTK/Common/System/vtkSocket.cxx, line 481
vtkClientSocket (0x7f988f3a6020): Socket error in call to connect. Permission denied.
ERROR: In /Users/senui/paraview/VTK/Common/System/vtkClientSocket.cxx, line 53
vtkClientSocket (0x7f988f3a6020): Failed to connect to server Senui-Mac.local:22223
ERROR: In /Users/senui/paraview/VTK/Parallel/Core/vtkSocketCommunicator.cxx, line 713
vtkSocketCommunicator (0x7f988bea9110): Can not connect to Senui-Mac.local on port 22223
Abort trap: 6
```
Even though it says its trying to connect to port 22223, I am absolutely sure I have it to 22222 in both ParaView and the Python pipeline. Again, no problems on Linux (following the exact same procedure). A colleague of mine faced the same issue a while ago (also on OS X).
Any suggestions on how to fix / debug this?
Best,
Ahmad
---
### Author:  [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)
#### Post date: [July 16, 2018, 2:42pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/2 "2018-07-16T14:42:21Z")
Thoughts @Andy_Bauer ?
---
### Author:  [@Senui](https://discourse.paraview.org/u/Senui)
#### Post date: [July 22, 2018, 3:19pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/3 "2018-07-22T15:19:49Z")
@cory.quammen I had created a gitlab issue before: [https://gitlab.kitware.com/paraview/paraview/issues/17752](https://gitlab.kitware.com/paraview/paraview/issues/17752)
At the end of the discussion @Andy_Bauer said he does not have a Mac and asked if I could post it in the mailing list so that someone else could take a look at it.
---
### Author:  [@Senui](https://discourse.paraview.org/u/Senui)
#### Post date: [August 23, 2018, 1:07pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/4 "2018-08-23T13:07:07Z")
Any update on this?
---
### Author:  [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)
#### Post date: [August 27, 2018, 12:50pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/5 "2018-08-27T12:50:53Z")
I saw in your GitLab issue that you could not connect that Mac client to your server. The reason, as indicated by the error message
```auto
ERROR: In /Users/ahmad/ParaView-v5.4.1/ParaViewCore/ClientServerCore/Core/vtkTCPNetworkAccessManager.cxx, line 413
vtkTCPNetworkAccessManager (0x7f97ca5003e0):
**********************************************************************
Connection failed during handshake. This can happen for the following reasons:
1. Connection dropped during the handshake.
2. vtkSocketCommunicator::GetVersion() returns different values on the
two connecting processes (Current value: 100).
3. ParaView handshake strings are different on the two connecting
processes (Current value: paraview.5.4.renderingbackend.opengl2).
**********************************************************************
```
is that your client and server versions are mismatched. Please ensure that you have the same version for both the client and the server. If you have built ParaView, ensure that both the client and server have the same rendering backend (CMake option `VTK_RENDERING_BACKEND:STRING=OpenGL2`). Once you have successfully connected a Mac client to your server, hopefully the Catalyst example should work.
---
### Author:  [@Senui](https://discourse.paraview.org/u/Senui)
#### Post date: [August 27, 2018, 1:25pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/6 "2018-08-27T13:25:28Z")
Thanks for your reply. I tried again to connect the ParaView client with the server (both built with the exact same CMake options). I was able to connect `pvserver` with the client. I got the “Client connected.” message on the server.
But still when I try to run the Catalyst example, it gives the message like in my opening post. I tried changing port numbers (on both client and server), but same problem.
---
### Author:  [@PatrickConradCH](https://discourse.paraview.org/u/PatrickConradCH)
#### Post date: [August 14, 2020, 3:32pm UTC](https://discourse.paraview.org/t/cannot-connect-to-catalyst-live-visualization-on-mac-os-x/301/7 "2020-08-14T15:32:35Z")
For the sake of future internet searchers, there’s an explanation and workaround here: [https://gitlab.kitware.com/paraview/paraview/-/issues/20150](https://gitlab.kitware.com/paraview/paraview/-/issues/20150)