Error on bookmark: "The Object is not available."

I have a user who gets an "The Object is not available." error when attempting to access a particular bookmark. Comparing her security profile to the LBI security in place, she is in the group which is listed on the LBI dashboard, module and link as having access to the task.

Since I know by default our bookmarks are set to 'Deny', I went into bookmark manager thinking perhaps the group did not have access there. However, one of the groups she is a member of does in fact have access set to 'Allow'.