How to turn off a weird "box" cursor and selection behavior in Netbeans?

This key combination (Ctrl+Shift+R) is used to open types etc. in Eclipse, so when switching to Netbeans many people will get stuck with this.

One possibility is you have the Rectangular Selection plugin installed.

However, the more likely candidate is the rectangular selection feature in the editor core. Find the button on your edit toolbar, and toggle it off. As per helpful comments below, this can accidentally be switched on (and toggled back off again) using:

• On Windows and Linux: Ctrl + Shift + R
• On Mac: Shift + Meta + R
• On Mac, if the above does not work: some folks have reported that Shift + Command + R worked for them

You can use it to write multiple lines with the same content as sublime text

See this examples:

https://blogs.oracle.com/netbeansphp/entry/rectangular_selection