Preview null null

[Shades.]

So I'm having a problem when previewing a post it puts a null null at the end. Any ideas what could be causing that and how to fix? When I click on "Post" the null null is not there just during the preview. Using SMF2.0.17 (See attachment)

[vbgamer45]

What browser? Any mods installed that might affect posting?

[Shades.]

Firefox...and I just uninstalled the last mod which was "Snowflakes" and seems the problem went away.