Starting with version 4, Blender requires OpenGL 4.3 or later.
A lot of older (and not-so-old) hardware only supports OpenGL 4.2.
You cannot use any current version of Blender.
In this case, you can use Blender 3.6, which requires OpenGL 3.3.
It has been discontinued, but it is still functional and useful in certain situations.
On Ubuntu 22.04 and 24.04, the Blender 3.6 executable works perfectly. On the latest 26.04 release, it has graphical glitches when reflections are enabled. It cannot be used in this state.
My question is: is this a bug in 26.04, or is it an intentional change? And is my only option to buy new hardware or go back to Ubuntu 24.04?
This site is a community forum, your chances to get a satisfying answer for such a question here are rather low I guess, I’d ask in a Blender forum like https://www.blender.org/support/
I think (I might be wrong indeed) that CAICOS uses the old radeon driver which is open source…
If it is actually a limitation with the older hardware like the OP states, I doubt there is a way out.
You will likely not be able to downgrade the OpenGL libs and even if you could, the newer blender seems to be built and linked against the newer OpenGL so there is no way out here either unless you compile your own blender from source and make it link against the older GL, which is why it amazes me that a blender dev sent you here, they should know what they linked against…
I think we’re talking about different things. Blender 3.6 is a discontinued version based on OpenGL 3.3. It works perfectly on any GNU/Linux distribution, and it even works on Windows 11.
The error occurs in Ubuntu 26.04 on any hardware that doesn’t support OpenGL 4.3, but you could give it a try, I have some old graphics cards lying around.
