"Out of memory" error, Tahoe 26.3.1

There are 2 reasons for the “Your system has run out of application memory” dialog box.

A. Your boot disk has very low free storage, and macOS cannot create page/swap files to offload virtual memory contents to disk. Depending on how much virtual memory is being called for, anything under 50-100GB of free storage may trigger the message.

Apple menu (upper left corner) -> About This Mac -> More Info... -> Storage (scroll down a bit) -> Storage Settings...

B. A process (or set of processes) has asked macOS for excessive amounts of virtual memory address space. In order to keep track of the virtual memory address space, the kernel creates virtual memory page tables. If there is a memory leak (process asks for a virtual address range, forgets to give it back, asks for another range, forgets again, wash, rinse, repeat), eventually there are so many page tables created there is no memory left for applications, and you get the “Your system has run out of applications memory”.

Look at

Applications -> Utilities -> Activity Monitor -> View (menu) -> All Processes -> Memory (tab)

you can see what processes are using lots of memory. Many of these processes will be background agents and daemons used to provide many of the macOS services, as well as your applications.

Also keep in mind that each web browser tab will be a separate process running its own Javascript. If you have lots of browser tabs open, or if one of the browser tabs running Javascript with a bug in it, it is possible these browser tabs will add up to a lot of virtual memory demands, but no individual tab will look all that big.

I have personally had the "out of application memory" ever since upgrading to macOS 26.x Tahoe last year, plus I have seen numerous reports on this forum. The only version of Tahoe which seemed to mitigate this issue was 26.2. macOS 26.3 brought the problem back but not as severe, and 26.3.1 still has the issue. I have not yet tried the just released 26.3.2 update.

Usually one of the apps in the list will be the main offender utilizing the most memory.....usually it will be a huge number. Or maybe you just have too many apps & documents open at once....probably a bit of both.

Regardless, you workload is probably exceeding the physical memory by a lot which means you should either modify how you use your computer (close other apps except for the app which needs lots of memory), or purchase another computer with sufficient memory for your workload.

From my own observations, Tahoe seems to have changed how it handles memory & storage (especially not releasing memory/storage) compared to older versions of macOS. On older versions of macOS the system would usually have spinning wheels to alert a user to a problem, but with Tahoe I never see any spinning wheels....suddenly the system alerts to "out of memory" error and pauses apps sometimes bringing the system to a nearly complete freeze (at least it now leaves about 10GB of Free storage space instead of running it down to 0).

You should try updating to macOS 26.3.2 which was just released the other day....maybe it will help to minimize the problem.

When this problem occurs, especially with multiple apps being paused.....you should Force Quit each app starting with the one using the most memory. Once each Paused app is Force Quit, then reboot the computer. I've seen system stability issues on early versions of Tahoe if I tried to relaunch apps which were unpaused/Resumed after Force Quitting the app using the most memory.

You can look at the Memory Pressure graph in Activity Monitor to keep an eye on memory usage. If you see red, then you are overloading the system with your workloads.....if you see yellow, then you are borderline on overloading the system. Even if the memory pressure graph is green.....if you see Swap or Compressed Memory using GBs, then you are probably overloading the system as well. If you are overloading the system, then either change how you use the computer such as closing apps & documents when not being used, or purchase a computer with more memory to handle your workloads & how you use the computer.

Give the following a try. It probably won't solve the problem but it can clean up some system and application temporary swap and cache files and repair the directory: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

Most likely a memory leak in InDesign. Make sure you keep the app updated, but unless it happens again I would not worry about it.

It could have been caused by a glitch, a run-away or a failed process.

Use of Pro App's in conjunction with other App's might require more frequent restarts to free up RAM.

If it happens again or the Mac is acting sluggish..?

You can use the Activity Monitor to view the RAM usage.

see Check if your Mac needs more RAM in Activity Monitor