Problem with file explorer

[AcrobataLoco]

Can't get rid of this problem, there is a misterious bar in my file explorer that I can't get rid of.
I've updated recently from win10, used some theme apps, now that I updated, this weird bar appeared and I couldn't figure out how to fix it. Any ideas? The app did not allow me to change that

[Abdelrhman-AK]

Mainly WinPaletter doesn't do this issue.

• Did you use WinPaletter before or after the upgrade?

• Did the issue appear before or after using WinPaletter if this issue appeared after upgrade?

• Try to return to default Windows theme in Windows Settings > Personalization

• Type this in Command Prompt as administrator and restart your Windows: sfc /scannow

Tell me if this issue still persists after doing the previous steps or not.