When you get a message that you need to update plugins while opening a file it means the file was saved in a newer version of InDesign than the one you are using. It's a terrible message- there are no plugin updates to solve that problem. Ask the person who supplied the file to provide a .idml file instead (and expect some conversion loss), or upgrade to the correct version of ID.
I inherited the job of recovering files created during the period of time my company used Adobe CC and after analysis decided to go back to using CS5 and CS6 software they had purchased. I'm forming the opinion now that it will be easier for me to simply reconstruct the documents either in another program or ID CS5. There may be serious differences between CS5 and CC versions but for the publications this company produce, I can't find any useful difference between the two versions or at any rate, nothing I can't overcome with CS5.
I'm not surprised to discover what you've said seems to be correct. Just another example of too much focus on profit and not enough on product perfection. When I compare some of my magazines created with an Atari system, the only functional difference is the colour and the layout. Both of which could be easily brought into line with current design trends. I agree absolutely with your description of the message. All it seems to have done is create a plethora of virus riddled torrents unknowing people are poisoning their computers with.
Thanks for the reply. I think this company's answer is to recreate those documents that were not converted to .dml files before removing CC from their workstations.
You could download the CC trial on a machine where it wasn't previously installed, or buy a one-month subscription to CC, to do the export if it would save you a significant amount of work.
And I agree with you, at least for a print workflow, that there hasn't really been anything compelling added to ID since CS5.