sidebar widget not appearing!

what’s up-

I’m using the BLIX default theme 202

I’m having problems with my sidebar widget, I installed it but couldn’t get the sidebar widget item to show up.

After I edited the sidebar.php file. I got the Header Image and Color and Sidebar Widget to show up in the presentation tab. BUT when I click the Sidebar Widgets tab I get a blank page.

Same thing with the Header Image and Color when I click it, I get a blank page, the only thing that shows up is the title and buttons-

Header Image and Color
Font Color Upper Color Lower Color Revert Advanced Save
The rest of the page is blank.

Can anyone help me fix this?
THANKS in advance for any help.