Copy app error: "The open file ulimit level is too low, please increase it otherwise changes will not be detected properly"

Question

When using Copy, I get this error:

Error: "The open file ulimit level is too low, please increase it otherwise changes will not be detected properly"

The application stops syncing when it appears, why, and how do I fix it?

Answer 1

1) Create file /etc/sysctl.d/60-copy.conf

2) Open that file and write:

fs.inotify.max_user_watches = 20000
fs.file-max = 800000

3) Save the file and exit

4) Go to the terminal and apply those settings by typing:

sudo sysctl -p /etc/sysctl.d/60-copy.conf 

5) Launch the Copy app again and it should work.