• My pc has 32GB RAM (windows 7 enterprise)
• Notepad version: 7.5.9 (64 bit)
• no plugins installed.

The last crash i just copied some random text and pasted it allot of times.

I tried you experiment and got a crash again (https://imgur.com/a/n1NYHhB). This picture also shows the exact error.

I guess TLDR… :-)

I found my lost files in the “N++RECOV” folder inside %temp%. But i’m still curious if the crash could be prevented.

• What version of Notepad++ are you using?
• What plugins are installed?
  • these first two, as described in the linked FAQ, can be found in the ? > Debug Info menu
• How much memory does your PC have? What is your memory usage before you start the experiment? (Ctrl+Shift+Esc > Performance > Memory)
• What is the exact procedure you use, and is it reproducible for you?
  • You said you “kept copying the same bit of information”.
    • How big is the block you are reproducing?
    • Did you copy once, paste N times? Or did you copy-all, paste, copy-all, paste (to double size each time)?
    • Does it matter what’s in the text, or does it only happen with a certain string?
  • Was it a new / unnamed file? Or did you start with a previously-saved/named file?
  • What are your settings for Settings > Preferences > Backup

For example, I could not repeat your circumstance by using:

Notepad++ v7.5.8   (32-bit)
Build time : Jul 23 2018 - 02:03:53
Path : C:\Program Files (x86)\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS : Windows 10 (64-bit)
Plugins : ComparePlugin.dll dbgpPlugin.dll DSpellCheck.dll MarkdownViewerPlusPlus.dll NppConverter.dll NppExec.dll NppFTP.dll PluginManager.dll PreviewHTML.dll PythonScript.dll XMLTools.dll mimeTools.dll NppExport.dll 

1. My Task Manager > Performance > Memory shows about 4.2G / 7.8G used… before I start.

2. Create new (unnamed file)

3. Typing a single line followed by a newline:

   This song is just six words long.
   

4. Ctrl+A (select all), Ctrl+C (copy), Ctrl+END (goto end), Ctrl+V (paste)

5. Repeat #3 until I had 2097152 lines (that’s 2M, so it goes over your “over 1 million lines”.)

6. From about the 500k-line version, the copy/paste got slow. When I tried to copy the 2M lines, and paste, I never saw the result of the paste (though it never crashed).

7. I started over (after closing the file, exiting, and reloading NPP), and this time my last copy was on the 524288-line copy. I then only pasted from then on out… The paste when my blank line was 5767169 never seemed to finish. But once again, I didn’t get a crash.

I cannot replicate your problem. So, unless you can show us exactly how to replicate your problem, it’s going to be hard for us to help you.