Layout issues, can't rename two of my layout IDs

[BHU]

I'm having trouble renaming two of my layout ID's, Saw an earlier post with the same problem but can't seem to resolve this. Anyone here on the forum come across this in A27? 
Could I have accidentally locked a layout? How do I unluck them? 

Operating system used: Windows 4060 Swe, full

[Botonis]

Is it just the ID all or the settings...?

Maybe then the layer that the layouts belong are locked.

Can't think something else right now.

[BHU]

Thanks for the reply Botonis
I can't see that any layers in my master layout are locked. It seems that only the ID is "locked".Becaus I'm allowed to change the Name on my Layout.

But it's not locked as a normal layer... because when i choose [Rename Layout...] to rename Custom ID and click OK  I can see the new ID changes in the Layout book for a millisecond and then reverts back to the old ID.