When the LED Bar is blinking red, it means the load attached to the light is too small in a non-neutral setting. In other words, if you are not using a neutral wire, you need to have your load (light) be at least 25W (NOTE: Not a 25W equivalent, but actually 25W). If it's not, a bypass module needs to be installed at the light fixture.  The Aeotec bypass is recommended. Fibaro bypass is not compatible.

The way the Gen 2 Dimmers work in a non-neutral setting is that they require at least 25W to be installed at the load (light) in order to let power seep through to the switch. If the load is below 25W, the switch will not work correctly and the blinking red light will signify this issue (in some cases, if it's a very small load, the LED Bar will not light up at all).