Error message "…Too many open editors.…" at dev. versions and RT5.9 RC 1

Dear friends.
Thanks for the great work on RT.
I usually work on two monitors in the layout mode “Multiple Editor Tabs in Own Window Mode” (Windows 10 Pro, Version 22H2, System build 19045.2251).
Since some development versions and also now with RC 1 I get the following error message:"Cannot load image ‘XXX’. Too many open editors. Please close an editor to continue’. All other layout modes work without problems, I can open “as much” photos as I want.

I have tried to manipulate something in the settings. But without result. I can reproduce this error on other machines. I couldn’t find similar topics in our forum. [the topic Bug - Too many open editors?, May '19 is not the same]
Does anyone have an idea how to eliminate the error? I would be grateful.

Best regards
Andreas L.

All other layout modes use just one editor window. In other words, you can just open 1 image after the other. This leads to the assumption, that you are low on memory.

Thanks, ChasingShadows.

And thanks for your suggestion. But see system info:

Prozessor: AMD Ryzen 7 5800X, 8-Core Processor, 3.80 GHz
RAM: 64,0 GB
Systemtyp|64-Bit-Betriebssystem, x64-basierter Prozessor|
Stift- und Toucheingabe|Unterstützung für Stifteingabe|
Edition|Windows 10 Pro|

You can see it’s sufficient RAM and the system is updated.

My workflow is to always open a series of several photos, three to nine or something like that. The photos have similar photo-technical properties. So similar motifs, WB, exposure, and so on. I tweak photos one by one as quickly as possible; copying the processing steps. This is the reason why I prefer the Multiple Editor Tabs In Own Window Mode.

The problem occurs if I open several photos in
- Multiple Editor Tabs Mode (one screen), i.e. more than 12 or similar,
- Multiple Editor Tabs In Own Window Mode - the message occurs after the third photo.
A few months ago, I tested how many photos I could open in Multiple Editor Tabs Mode ( on one screen), . There are 12 to 16 photos before the computer complains. (61Mpx = 1,2 GByte in RAM).

I guess it’s really a memory management problem. But in the current case, this is rather not caused by Windows. The error message comes from RT, not from Win10.

I am grateful for suggestions. Even if I have to edit RT files.

Best regards

I just did a little test on my, Linux, box:

AMD Ryzen 5 3600 6-Core Processor, 32 Gb + 15 Gb Swap.

If I open 12 ~75MP files, without doing any edits, I get an unworkable situation. Memory is down to 3.5Gb and about 1Gb swap is being used. I started viewing images at 100% and this immediately dropped my available memory to a tad above 1Gb and increased swap usage to 3.5Gb (this after 3 images).

Everything becomes very unresponsive and if I try to close one image it hangs and Linux tells me that the application became unresponsive.

RAW editing takes a lot of memory and having 12 to 16 61MP files open to work on really pushes what your machine can handle. I know you have 64Gb and not, like me, 32Gb but I’m all but certain that this is indeed memory related.

IIRC, there’s only a certain number of GUI handles RT can obtain from Windows. So this message isn’t about RAM/swap but about a limitation on Windows.