How many files can the new Arduino IDE handle?

This message is not a recommendation for a new program! How many sketches and libraries can you have?
IDE20_Notice
The instruction link gives tips for Unix operating systens, but nothing for Windows!

This is a known bug, which is tracked here:

The warning message does not indicate any problem. Please just ignore it.

The solution I found and it’s work for me is

add this line fs.inotify.max_user_watches=524288 in to /etc/sysctl.conf

and then run the command sudo sysctl -p

and then go to your vscode settings find a file called settings.json

and this line to it.

"files.watcherExclude": {
    "**/.git/objects/**": true,
    "**/.git/subtree-cache/**": true,
    "**/node_modules/*/**": true
  }

As I said, there are hints for Unix / Linux but nothing for Windows 10.