# Problem running Slicer on CentOS8
**URL:** https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413
**Category:** Support
**Created:** [November 3, 2020, 6:16pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413 "2020-11-03T18:16:13Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Yuting\_Deng](https://discourse.slicer.org/u/Yuting_Deng)
#### Post date: [November 3, 2020, 6:16pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/1 "2020-11-03T18:16:13Z")
I was having the same problems opening Slicer 4.11 with CentOS8. I have followed the methods mentioned above and made sure that all the missing libraries have been installed, but I still keep having the following errors:
```
[hermioned@localhost Slicer-4.11.20200930-linux-amd64]$ ldd /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so | grep "not found"
/home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5XcbQpa.so.5: version `Qt_5_PRIVATE_API' not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
/home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5Gui.so.5: version `Qt_5_PRIVATE_API' not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
/home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5Core.so.5: version `Qt_5.15' not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
```
I installed and updated libqxcb.so using `updatedb && locate libQt5XcbQpa.so.5` and then and` "strings -d /usr/lib64/libQt5XcbQpa.so.5 | grep Qt.*API"`, I get the result `"Qt_5.12.5_PRIVATE_API"`
I see the problem here is: Slicer is looking for Qt\_5\_PRIVATE\_API but I have “Qt\_5.12.5\_PRIVATE\_API”, they just have different names/versions.
Is there a way that I could tell Slicer to look for “Qt\_5.12.5\_PRIVATE\_API”?
---
### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [November 3, 2020, 8:38pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/2 "2020-11-03T20:38:01Z")
Slicer package includes Qt (Slicer-4.11.20200930 uses Qt-5.15.1). When you run the application using the “launcher” (`./Slicer`), the launcher sets up LD library paths so that Qt bundled with Slicer is found. If you simply run `ldd` (not via the launcher) then you will get false alarms, as the correct paths are not set up.
What happens if you run Slicer using the launcher (`./Slicer`)?
---
### Author:  [@Yuting\_Deng](https://discourse.slicer.org/u/Yuting_Deng)
#### Post date: [November 4, 2020, 6:49pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/3 "2020-11-04T18:49:44Z")
Now it works! Thanks so much!
---
### Author:  [@muratmaga](https://discourse.slicer.org/u/muratmaga)
#### Post date: [November 4, 2020, 7:22pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/4 "2020-11-04T19:22:25Z")
Sorry, what was the solution?
Or rather what was the original problem that ./Slicer didn’t work?
---
### Author:  [@Yuting\_Deng](https://discourse.slicer.org/u/Yuting_Deng)
#### Post date: [November 4, 2020, 7:37pm UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/5 "2020-11-04T19:37:50Z")
After I installed all the missing libraries, using:
> ```
> [hermioned@localhost Slicer-4.11.20200930-linux-amd64]$ ldd /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so | grep "not found"
> libQt5XcbQpa.so.5 => not found
> libQt5Gui.so.5 => not found
> libQt5DBus.so.5 => not found
> libQt5Core.so.5 => not found
> libxcb-render-util.so.0 => not found
>
> ```
Even though I still have the error message shown below, I am able to use `./Slicer` to open Slicer now
> [hermioned@localhost Slicer-4.11.20200930-linux-amd64]$ ldd /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so | grep “not found”
>
> /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5XcbQpa.so.5: version `Qt\_5\_PRIVATE\_API’ not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
>
> /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5Gui.so.5: version `Qt\_5\_PRIVATE\_API’ not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
>
> /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so: /lib64/libQt5Core.so.5: version `Qt\_5.15’ not found (required by /home/hermioned/Slicer-4.11.20200930-linux-amd64/lib/QtPlugins/platforms/libqxcb.so)
---
### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [November 5, 2020, 5:18am UTC](https://discourse.slicer.org/t/problem-running-slicer-on-centos8/14413/6 "2020-11-05T05:18:33Z")
When you run `ldd` outside Slicer’s virtual environment (set up by the `./Slicer` launcher) then the “errors” that you listed are expected to appear, that’s the correct behavior. You will not see the errors if you execute ldd with the launcher (`./Slicer`).