Viewport re-loading materials - Display problem - Since C4D 2024 and 2025

[Lebenzet]

Hi !
NB : there is already a topic on that subject (https://forum.corona-renderer.com/index.php?topic=40735.0), but visibly it is not solved. And for my part, I experience that problem with C4D 2024 and 2025. 2023 works fine.
The issue :
In my viewports, the materials are reloading each time :
- I change view F1 (top view) or F2 F3 F4 and go back to perspective view
- I switch interface
- I switch to another scene already opened

This problem is not scene-specific. It appears with all my projects.

Note : When I switch to another camera in perspective view, there is no problem : the viewport keep all materials/textures in cache.

With large scene with lot of materials, it is absolutely unusable !
So I'm forced to work with C4D 2023. I can't update to C4D 2024 or 2025.
I checked all my preferences. I try to use a default configuration where I just specified the path to the textures.

I use the last version of Corona 12 hotfix2
Mac Studio M1 Ultra 128Go
Mac OS Sonoma 14 up to date (I'm waiting sonoma 15.1 before updating)

Thanks for help.

[masterzone]

It happens to me too, very annoying... I don't know if this issue is related to Corona Render or if something else has changed with the Redshift integration in the viewport... Anyway, this material refresh issue is very annoying.
Alex

[Lebenzet]

I uninstalled Redshift. And the problem remains....

[luis.lab]

Hi!
Also happens to me. Quite annoying to wait for all material previews to render each time I open a scene, before did not happen.
Using the latest Daily in C4d 2025, Win
Best
Luis

[Lebenzet]

I've just dowloaded and installed the last update od C4D 2025. No change. The issue remains...
So annoying.

[Core2000]

I can confirm the problem.
MacOS 15.01, Corona 12 HF2, C4D R2025.0.1

[bnji]

Hi there @everyone,
Thank you for bringing this to our attention.
I'm wondering, does the issue persists if you use a different render engine under the same conditions? (same number of objects, materials, etc.)
We'll investigate this on our end to see if we're able to reproduce it.
Additionally, could you please provide your HW specs? Just to double-check if this is something related to HW.
Looking forward to hearing from you.

[burnin]

Have you tried deleting C4D preferences?

//Note to debug:
1.) Make a backup.
2.a) If deletion resolves your issue, reconstruct former structure - add back directories one by one
/iterate large structures for faster solution, split stages in half, to see which one is causing issues.
2.b) If not, return to former state.
3.) Report back.

PS/Edit
Same goes for resolving plugin conflicts.

Edit2
Observe, check console for reports.

[Lebenzet]

So I recap :

My Configuration :
• C4D 2025 (2025.0.2) or 2024 (C4D 2023 works fine)
• Corona 12 hotfix2
• Mac Studio M1 Ultra (128Go RAM - 2To storage)
• Mac OS Sonoma 14

This problem is not scene-specific. It appears with all my projects.

I tried to delete C4D preferences
I tried to delete everything and try with a clean install of C4D/Corona with no customization. I try with just one cosmos object (Coffee Stall 118/20 for exemple) displaying the full mesh.
I can't do anything simpler !

It doesn't solve anything. The problem is present with C4D 2024 and 2025.
-> C4D 2023 works fine and so, I'm forced to use this old version.

You asked me : could you please provide your HW specs?
What's HW specs exactly please ?

Thanks.

[Lebenzet]

I Assume HW means Harware.
I've already specify this many times :
My Configuration :
• C4D 2025 (2025.0.2) or 2024 (C4D 2023 works fine)
• Corona 12 hotfix2
• Mac Studio M1 Ultra (128Go RAM - 2To storage)
• Mac OS Sonoma 14

[TomG]

As a note about repeating hardware configurations, please do on each ticket or separate forum thread - we won't be able to recall by username exactly what hardware you have, so would need it for each new report where it may be relevant (e.g. faster for you to copy paste the hardware specs than for us to search past tickets and forum threads from you to try and find one that has the hardware listed, and I am sure you'd all rather we spent that time working on your problem). We appreciate the info you send in!

[luis.lab]

Hi,

If it helps with anything, in investigating the problem.
I realized the preview of materials reloading takes way different times depending on how textures are linked if in Asset Browser, local, or full path.
Eventually is still related to the long-time issue of the Asset Browser links.

Best
Luis

[Lebenzet]

My Configuration :
• C4D 2025 (2025.0.2) or 2024 (C4D 2023 works fine)
• Corona 12 hotfix2
• Mac Studio M1 Ultra (128Go RAM - 2To storage)
• Mac OS Sonoma 14

As a note about repeating hardware configurations, please do on each ticket or separate forum thread - we won't be able to recall by username exactly what hardware you have, so would need it for each new report where it may be relevant (e.g. faster for you to copy paste the hardware specs than for us to search past tickets and forum threads from you to try and find one that has the hardware listed, and I am sure you'd all rather we spent that time working on your problem). We appreciate the info you send in!

OK I understand. Count on me.

If it helps with anything, in investigating the problem.
I realized the preview of materials reloading takes way different times depending on how textures are linked if in Asset Browser, local, or full path.
Eventually is still related to the long-time issue of the Asset Browser links.

I guess you're right, BUT note again that, on my machine, there is no problem with C4D 2023. The problem occurs with C4D 2024 and an above.

for the moment I don't want to upgrade to MacOS Sequoia. But I'm going to test on my home iMac M1 (with runs MacOS Sequoia) to see...