Studio 5000 resiliency versions?

[tlf30]

So just today I was reading a tech note about v20, and ite mentioned v20.03 resiliency update. After searching the forums I gather that there were possibly two of these (one in v20 and one in v21) and they are incompatible with other minor versions of the same major version. But what advantage was there to the update? Why were these versions a thing? Was there something specific that they were trying to accomplish?

Just curious

 

[alan_505]

I think it was something to do with a government rule/law, but Ken Roach will be able to confirm or explain it.

 

[plvlce]

iirc the change was security-related. If I knew the details I've since forgotten them.

 

[joseph_e2]

My recollection is also that it was security related and it seemed to be a faster than normal release too. Was it responding to Stuxnet maybe? Or something similar?
They subsequently released a newer minor rev that fixed the minor rev incompatibility issue so you can install the latest minor rev of the software and still go online with all minor rev processors.