Internal server error attempting to change 'Until' for a recurring event

[swickr]

#60 requests the ability to remove canceled meetings. That's more important to be able to do for a recurring meeting that has been scheduled far into the future.

A workaround for the recurring meeting case is to update recur Until. When I attempted to do that by choosing a (canceled) event ocurrence in the current week (i.e. still in the future), selecting 'Edit this and future occurrences' and changing 'Until' to the day before the event was scheduled, I get "Internal server error".

Changing Until to be the same day as the future event appears to have successfully removed the subsequent occurrences but, of course, it leaves the one upcoming occurrence still tagged 'Canceled'.