Please add more detail info about your actions before you got the crash

And please write here info from LibreOffice's Help-About dialog

What Linux distro do you use?

My distro is 
Distributor ID:	Debian
Description:	Debian GNU/Linux 9.13 (stretch)
Release:	9.13
Codename:	stretch

I noticed I get that crash using Animation
Definition / Emphasis /bold flash then make a try using Shift-F5.
It seems that I get it only using Emphasis. Entrance, for example, works well.
The crash occur when the display is switching (following shift-F5)

Also could you give a try at https://wiki.documentfoundation.org/QA/FirstSteps ?

Corrupted user profile : Same crash

Graphics-related issues : UI Render : default; VCL: gtk3

User profile was totaly removed to let LO create a new one.

Since you quote r600_dri.so, did you try specifically:
- https://wiki.documentfoundation.org/QA/FirstSteps#Graphics-related_issues_.28OpenGL.29
and above all:
- https://wiki.documentfoundation.org/QA/FirstSteps#Graphics-related_issues_.28Skia.29

You can also type this on console
export SAL_USE_VCLPLUGIN=gen;soffice
and give a new try.
It'll allow to know if it's gtk3 related in a way or not.

BTW, Debian 9.13 is the previous Debian stable (so contain old versions for desktop use, including LO), how did you install LO 7.0.3.1?
Do you use multi repo (Stretch + testing), did you install deb packages, or things like snap or flatpack?


(In general stable Debian versions are more for servers)

As I don't use Open GL I didn't do anything with Graphics-related issues (OpenGL) as UI Render for me is default; VCL: gtk3. Same for Skia.

"Check if the following string appears in Help ▸ About LibreOffice: "UI Render: GL.
If there is "UI Render: default" instead, it means the symptoms aren't caused by OpenGL, and the rest isn't applicable."
__________
Using export SAL_USE_VCLPLUGIN=gen;soffice works ! There is no more crash.
However, I had some logs redirected to the console showing :
***
Running DIL (3.22.0) Version
DtsDeviceOpen: Opening HW in mode 0
DtsDeviceOpen: Create File Failed
DtsGetHWFeatures: Create File Failed
***
__________
You're right about Debian 9 and Office 7.
I installed LibreOffice_7.0.3.1_Linux_x86-64_deb file via synaptic.
The release 5 is still in place into my repository and works well without any crash.
Of course, both releases are not used at the same time.

good news for the workaround with gen rendering.

I know it takes some time but you may give a try liveusb/dvd so you don't lose your current install and customizations.
Of course, perhaps you'd still reproduce this because of a bug somewhere between LO/gtk3/graphic card driver.

<digression>
I use Debian testing (quite up-to-date, safer than sid), I think you should give a try to a more recent version of Debian, at least the last stable and only if it's a server/production machine.
The always safe way, whatever the distrib, it's to make backups (and don't forget to test them too to know if they're reliable!)
</digression>

Yes, I didn't upgrade my Deb version because time.
But I'm going to do that as soon as possible.

I actually give some sub-marine biology trainings via Zoom and I need this is the reason why I use impress.
My try with LO7 was mainly to see if the notes are better displayed than with LO5. Unfortunately, it is still unusable.

Many thanks Julien for advise and assistance.

Dear PhLinux,
A new major release of LibreOffice is available since this bug was reported.
Could you please try to reproduce it with the latest version of LibreOffice
from https://www.libreoffice.org/download/libreoffice-fresh/ ?
I have set the bug's status to 'NEEDINFO'. Please change it back to
'UNCONFIRMED' if the bug is still present in the latest version.

Hi Xisco Faulí,
I just give a try with rel 7.1.0.3 with my deb Stretch 9.13.
It works without any crash using Custom animation
- Category: Emphasis
- Special:Bold flash

Congrats and thanks
Rgds
PhL

Thank you for your feedback.
Let's put this one to WFM then.