Thank you for your bug report. Plugins in sylpheed-claws are exclusive to their particular version of the program. Are you by any chance trying to load a plugin from the gtk2 version of sylpheed-claws into the (older) gtk1 version?
Thank you for your bug report. Plugins in sylpheed-claws are exclusive to their particular version of the program. Are you by any chance trying to load a plugin from the gtk2 version of sylpheed-claws into the (older) gtk1 version?