Comment 7 for bug 1003185

Same issue here, on a complete different configuration:

When taking a screenshot and the program starts, the error popup appears for each tab that gets loaded in the main window. After that the tabs are non-closable and throw this error message on the console when the x on the tab is clicked:
*** unhandled exception in callback:
*** Can't call method "cancel" on an undefined value at /usr/bin/shutter line 5737, <DATA> line 19.
*** ignoring at /usr/bin/shutter line 2921, <DATA> line 19.

Config:
Shutter 0.89.1 Rev. 1228
Archlinux (installed from AUR, so basically directly compiled from the newest code)
i3 window manager with as slim a setup as possible (only window manager and basic gui-tools)
x86_64