Problem with the Task Bar Icons

[AntonMarinski]

Hi,
So, today I decided to give my Raspbian a new look... I was setting up stuff in the Theme and Appearance Settings and when I pressed on "Apply" this happened: (see attachment)

Converted_file_226a5a63-min.jpg (58.63 KiB) Viewed 199 times

Does anybody know how I can fix this? I have tried some stuff (resizing the menu bar, applying different themes, etc.) but nothing seems to work...

I am quite a noob when it comes to linux, so help will be greatly appreciated!
Thanks in advance!
Anton