I think I’ve fixed reblogging not working on tag pages. It looks like it happened if you turn “Blog Selector” off, causing XKit to set the blog id to be blank, causing this.

I’ve just pushed version 2.0 that should fix this bug, especially if you have Blog Selector unchecked from your preferences. If you still get an error message, please let me know by an ask.

Also, thank you so much to those who have helped me identify this problem. =3