Well, have you actually created a path in the first place?
i am actually creating it but the arrows are not showing.
applies the effect but the arrows are not visible.
I initially wondered if it was to do with GPU acceleration, but I tested turning graphics processor off, restarted, and while the blue arrow was less well resolved, it did still show. So I am now wondering if Deactivating Native Canvas will resolve your issue. It seems to fix a lot of display related issues.
Lutz, Path Blur opens with a blue arrow for the path as below.
Looks like you're using an older version of Photoshop, can you post your system info, in Photoshop go to Help > System Info, hit the copy button and paste the entire thing into this thread
Always a concern Ged. A screen shot of the OP's Creative Cloud app would be
useful interesting to see. 😉