I also checked when the game path was without any spaces, no diacritic marks, when the game had already installed Reshade, and as performing update, and also when it was fresh installation, as DX9, DX10/11/12. No success.
In the very beginning of using 4.5.4 I only picked all shaders, and since then they are picked all the time, so I can't test whether it has any influence on this bug.
I afraid that lot of people might have this bug so the fix will be highly awaited.
This has already been fixed weeks ago (on GitHub). But won't be available until the next release of course.
Really easy to circumvent too: just type something in the text field next to the "..." button so that it is not blank before pressing it.