the topic is that all my audio files already analysed and I must do an new analysis for update the program.
You did not mention whether the "backup" was from v19 or v18 or if it contained previous analysis data?
I just installed my first copy of v19 - with v18 still installed and the v19 install simply converted my v18 library to v19 format. I now have two versions installed side by side. But when I opened my new v19 - I did not get any indicator of the library needing to be rescanned.
If you are restoring a v18 backup into v19 - the analysis has changed dramatically - and if your restored backup has none of the analysis data that v19 considers to be "current" - it's going to rescan. Do remember that the "analysis data" is stored in the library itself. Just because your files had analysis done on them at some point in the past - does not mean that MC will look at them and bypass them just because they happen to have some analysis metadata in them.
I believe MC is trying to get your "restored" library current (becuase you have analysis ON during import) and that means re-analyzing the files to get them in there. I could be wrong tho...
VP