There is an issue with synchronizing data.

Yes I am getting the same error. Could someone please help.

me too. Someone any idea to fix it?

I changed the theme to default. Deactivate all plugins, notting is happend. No reaction. Same problem.

Me too. Can somebody help or tell what I should do with it?

Hi,

This is probably to do with the permalinks, should show a message at the top when using the plugin saying you need to activate pretty permalinks.

This just means go to permalink section and choose anything other than the top option, though I would say use the post name option.

Should work now.