I can't open developer tools

[Bo_HuRE4200]

If I'm not mistaken the key f12 is responsible for developer tools do ya? But it doesn't work. My version is 1.6.1)))

 

[Hyouryuu-Na]

Are you using MV? Try f8. If you're using a laptop and only f8 doesn't work, try function key+f8

 

[Andar]

This is a known problem since 1.6.x if your project is not of the same version as your editor.
Please go to your project js folder, open rpg_core.js with a text editor and check the version number in the title line (no number means 1.0).

If it is older than 1.6.1, then you either need to downgrade the editor (if you can't update the project due to plugin compatibility) or update both your project and your plugins to 1.6.1 versions (1.6.2 is identical to 1.6.1, the only difference was for the japanese versions)