HI PriceCzech
I also had this issue using Chrome. As mentioned IE works perfectly but I did run into a few issues myself. Firstly, I had to upgrade my NVR to the latest version. The other thing I was stupidly doing was not pressing the '+' icon in the top right hand corner to add a new tripwire. I use a 5 series NVR so not sure if it is any different for you. The way I set mine is like this:
Connect to the NVR via IE
Click the setup tab at the top
On the left hand side click event, then select IVS
Choose whatever channel you want to make changes to
Just underneath the channel number next to 'rule type' click the '+' icon
Then click on the tripwire number on the table directly below
Click draw rule just under the camera image
Left click on the image to draw your lines and right click to end the tripwire
Press OK
You can then tweak the Parameters config
Done!
Apologies in advance if this is covering what you already know
Thanks