The operation could not be completed due to insufficient system memory

i felt the same problem and i just turn off my auto save , it was solved well

I think you must close all other programs. Or creat your project in another drive.

Please check if your media folder is read-only. I had this same issue, and once I disabled read-only on my drive/media folder, it went away.

I am experience the same issue. Nothing else is open and I restarted my computer. Only program pulling sufficient memory based on my activity monitor is Premier. I can't copy and paste sfx or clips from an old project that I opened via the media browser. I was able to do this just yesterday and I have made 0 update or changes to either my IOS or premier (auto update is not turned on either). This is happening in multiple project files as well so the files not corrupt.

This happened to me recently. (Premiere CC 2018 on Mac)

I figured out that it only happened if I was cutting & pasting clips that included media that had not been imported into the project, i.e., pulling a clip from finder directly onto the timeline without adding it to a bin. Cutting and trying to paste that clip reliably brought up the error message.

Adding the clip to a bin got rid of the problem. No relation to memory or CPU usage. Just yet another misleading error message.

Adobe have not resolved the errors surrounding drag-and-dropped media for several iterations now. For example, pulling a clip from finder into the source monitor and pressing "Reveal in Project" will crash Premiere every time.

I have been having the exact same problem since the update to CC 2018. Haven't been able to find a solution. :/

Only alternative I've been able to work out is to import the entire sequence using Media Browser into the project, which is way more than I often care to.

(How would it be able to copy ENTIRE sequences and not a clip in a sequence? Points to a software issue over hardware.)

I have seen this when I have too many programs open at the same time.