If there is no exclusive use by- law making the owner responsible then it is the OC’s responsibility. If the person who did it has gone, then you can’t require a by- law so you’re stuck with it.
A TV aerial is slightly different – someone may have put it there, but generally I believe the OC has to provide that sort of amenity. How they provide it is up to them.
Solar panels and air conditioning would be OC responsibility unless they passed a resolution not to replace or repair it, but I think that resolution has to be unanimous.