I have a pretty bad problem with OpenGL UI’s and Ableton on Windows.
I uploaded a video demonstrating the issue here: Video showcasing the issue
And also uploaded a simple test project for reproduction here: Test Project
Once an UI has a little more work to do, Ableton will completely “lock you out” from interacting with it, when you open more than one of these “heavy duty” UIs. Depending on the workload the issue appears on 2 or 3 or more simultaneous UI instances.
The interesting part is, that Ableton doesn’t really seem to be frozen, as the save-popup on Window close indicates and also task manager is fine (although showing higher GPU usage, 5-10%). But any interaction with the mouse on Ableton is just gone, once you open the 2nd UI window.
The build in my video was made on the latest Master branch. I’m on Windows 11, but the issue also occurs on Windows 10. We had users report this over a range of our plugins and unfortunately the issue can be reproduced with my simple test project up there. It only happens on Windows when OpenGL is active. When I’m disabling OpenGL, everything is fine, although performance of course suffers.
I’m testing this on an AMD Radeon RX5700XT (latest driver), which should well be able to handle this. Users who report the issue are running high-end graphic cards like RTX 2080 (and generally high-end machines) as well.
Of course my test project is meant to stress-test this issue, but I have the exact same issue on UIs, that are just a tad bit more complex - a couple sliders and knobs, maybe one visualiser. The more simple UIs of our plugin range allow for 4-5 instances before this issue occurs.
Since I am able to reproduce this with my super simple test project up there, I would assume the issue lies with JUCE, but I’m happy to be told what I’m doing wrong instead. I get, that the UIs might start lagging when I’m doing too much work, but this complete freeze-out just because of opening a 2nd instance seems bad. I can easily open 10 instances of this as Standalone builds without any issues (other than performance starting to suffer a bit after 7-8 instances).
//Edit: Also, no issues visible on Visual Studio Debugger, when this happens, everything seems to be running smoothly as far as I can tell…