In the section [NbOfActions], these actions both appear twice:
S&M_SETCCLANES_ME=8 ; [MIDI Editor] Restore displayed CC lanes, slot n
S&M_SAVECCLANES_ME=8 ; [MIDI Editor] Save displayed CC lanes, slot n
No, this is not a confusion with S&M_MESETCCLANES=8 and it's save counterpart :).
At the moment we have to edit both appearances of these lines to make changes to the number of slots for the new(ish) MIDI editor versions of these fine actions.
At first we thought the actions were restricted to the default 8 slots, because if you edit only one of the twins, they will just reset to 8 when Reaper is opened. But that part is working fine as soon as you edit both (or delete one of the twins - but how to make sure you delete the evil one :D).
Oops, plain dupe actions!
Thanks for the report gofer, will be fixed in the next pre-release (v2.5.1)