I have one of the first metabones adapters for canon EF to E, the ones where there were flare issues which meant you had to black flock the inside, I used this with no problems on an A7r but now it will not stop the lens down on my A7r II.
Will I have to buy a more modern version to get this functionality?
I have never changed the firmware on the metabones since it was purchased (if it's not broken don't fix it)
I own two Metabones adapters, one is the third version and one the fourth version if I remember correctly. Both adapters work as intended with my A7rm2, but I think I have updated the firmware of the older one.
I just checked Metabones website : only the adapter Mark IV can be updated. The Mark III has to be sent to Metabones for servicing.
What the updates does concerns mainly AF, which is made compatible with the hybrid AF of the Arm2. If you have problems with the aperture, first check that both the adapter and the lens are well fitted together. It occurs me sometimes that the contact isn't fully linked and that prevents the adapter from working.
That fact just remembered me why I had got the IV version : it was too cumbersome to send it outside of the country and I didn't want to go to the trouble of treating the adapter against flare.
Note that without the update or with the III version of the adapter, focusing will remain as slow as with the A7r, because only contrast detection will be used.
There is more info on the Metabones website :
Metabones®