Done.

OS Windows 12 Server

I tried it with another BI instance(clustered).

Same results. Sometimes chrome, IE and Avast browsers see custom.css, sometimes not, sometimes part of it. Sometimes any others css-s dissapears from developers consoles.

I think this is BUG. Why? Because I recall that sometimes styles crushed in OBI dashboards when I changes properties via Administration->Manage Themes.

There are only few options but I now think that works with custom.css somewhere inside.

But Ive found solution. You can change custom.css and another files on every node(if clustered), stop Presentation Servieces, undeploy/deploy or redeploy this folder and start Presentation Services.

That works

Thanks for helping

I didnt!

But in Windows problems with editing styles in shared folder without redeploying it quite similar to ones with fake styles.