Its possible that Sortd is clashing with another Chrome Extension you have installed. Unfortunately it is not possible to make sure Sortd works with all other Chrome Extensions, and as Chrome Extensions can be updated in the background any change in one Chrome Extension can break another. This is not a problem unique to Sortd but affects all Chrome Extensions to varying degrees.
To isolate if this is the problem please try the running Sortd in a new ‘clean’ Chrome Profile. Instructions on how to do this can be found here.
Please also see the section describing Chrome Extension compatibility.