I have tried creating several custom Event fields for a subscribed calendar, but after creating a field (and entering data for the current event) I'm normally prohibited from subsequent editing (or entering new) data into that field.
There is a consistent (but kludgy) work-around: If I enter the Custom Fields editing screen and create another custom field or delete an existing one (it doesn't even have to be an Event Field), and then click on Save & Close, I can then immediately edit either custom Event field (the original, or one I just created) for an event. But the next time I try to edit these fields (on the same event or a different one), the field is grayed-out and clicking on the field results in no response. This happens regardless of the field type chosen for the custom Event Field.
I've deleted and then re-created the custom Event Field more than once, yet the erratic behavior remains. Since this is a subscribed calendar, I initially thought that maybe even custom fields weren't editable when subscribing. But if I follow the above work-around, I can enter or edit information into the custom fields (but not the standard ones, which makes sense) so I can edit the custom fields, it just takes some annoying extra steps to do so.
I hope that this is a bug, and that once fixed I will be allowed to easily edit custom fields even for a subscribed calendar. Since these custom fields don't exist in the source calendar (and therefore couldn't be synched anyway), it doesn't seem like there should be a problem having them (and having them allows for some very useful "offsite" VueMinder-specific annotations).
Is this a bug or (more hopefully) am I missing a step/setting that would allow me to easily edit the data within a custom Event Field?