iPAD activation error using Apple Configurator (1.7.2) on OS X10.11.6 -4026 record incorrect

I am using "Old" MBPro running OS X 10.11.6 (El Capitain's last build?) in pair with Apple Configurator (1.7.2) to manage and prepare batch of devices.

Supervised mode is being set as well as few minor configuration elements like WI-Fi, etc. Nothing too fancy.

Since about a month (I'm not using this on a daily basis) no device was activated and all I get are the same errors:

ipad activation error -4026 record incorrect (on each device)

a) It is not a networking issue (checked multiple times using different networks, etc, firewall - ok, proxy, everything)

b) Those iPAD's were already prepared using this AppleConfigurator so it recognizes the devices, their descriptions, config, etc.

c) No such errors occured 2 months ago

d) The devices were wiped, removed from FindMyiPhone, prepared completely stock - still nothing

Can this be an issue with the fact that when setting the device into Supervised mode only the latest (10.3.1) iOS version can be downloaded and AppleConfigurator 1.7.2 may be incompatible with this one?

Unhappily, when trying to use AppStore I'm not able to update the AppleConfigurator as there is only 2.4 version available and this one requires OS X 10.12.X (and this MBPro won't receive it).

Has anyone faced similar issue? Any ideas how to deal with such problem?

I would appreciate any help with this issue.