I am trying library import for the first time, according to the blogpost on libraries and user files, this being necessary to store a sound from a library (just saving it not being enough)

It maybe that it is not working for you because you are unclear on the reason the function exists. Because if you believe "just saving is not being enough", then you clearly do not understand the reason for importing Library data.

The reason is: to repoint and document a new relationship between the Waveform data and the location Reference for the Samples they organize.

You need to ask yourself, is this something I need to do. If the answer is no, there is no need to Import Library data.

When custom audio data is placed in a Library, it is stored so that a permanent (ROM) Waveform Number is given for each custom audio package. Any AWM2 Parts that utilize these Waveforms are pointing to these Waveform Numbers. If there comes a time where you wish to create a custom Library consisting of data gathered from several different installed Libraries, that is a reason to "Import Library" data. (You will need to repoint data to new locations)

Let's, for understanding's sake, say you want to take data from two separate installed libraries and combine them into a new single Library... you would simply select the Performances you want from each Library (in two separate operations) and Import them into the User Bank (your work area). This action literally repoints the target on each AWM2 Element from its original Read Only Memory Waveform Number, to a new RAM based Waveform Number. The act of "Importing" (leaves a marker that) tells the Montage to gather all the information to make your Performance selections work in your new User Bank. And should you then SAVE this User Bank as a Library File, the Montage will dynamically give this new Library File a new ROM location for each of the AWM2 Waveform data.

By looking at the AWM2 Part's Oscillator screen you will observe the redirection of this data. Now when you then execute a SAVE operation (which documents this new User Bank as a new Library File), the new Waveform Number locations are documented.

So again, the reason for Import Library has a specific relocation purpose, not because saving once is "not enough", (not at all)!

_ You SAVE your imported data from the User work area to create a new .X7L Library file.
_ Because simply STORING a Performance from a Library location to a User location, does not "repoint" each AMW2 Element to a new Waveform Number location. Only IMPORTING does!

If you recount your steps, we'll point out exactly where you lost track of what you're doing...

yes, I know the reason, I understand there are samples that will not be there anymore if the original library is gone, that is explained in the blogpost about libraries.

and I want to import those few performances from the 2 libraries jupiter and roland posted by a nice user here recently:

https://www.yamahasynth.com/forum/roland-juno-jupiter-jv-2080-for-montage-user-banks-download

and then I want to throw out the original libraries since there are only very few sounds in them.

problem is, not all of those sounds get imported. some of the performances are mute in my user file. some of them work. the ones that don´t play have no active element at all.

could it be that the import function is not 100% reliable? trying to import several times, the same performances sometimes work and sometimes not.

No. It could not. (well, anything is possible) but let's just say it way more likely it's user error. Can you explain what you are attempting to accomplish?

As a test, it would be interesting if a factory initialization followed by the exact same user operations following initialization resulted in different performances "working" from one cycle of this testing to another.

I thought I explained what I´m trying to accomplish. Nothing more than importing the juno and jupiter libraries into the user file with "library import". Not all performances are working. Wondering why not. If it´s a user error, is the error in the libraries themselves? Because I don´t see what I could be doing wrong. "library import" is one single function with no options, so what could be done wrong by the user doing the library import?

But besides that, when you say "pointing to these Waveform Numbers" does that mean the waveforms do not actually get imported into the user space? (the blog is not really clear about that either). I tested erasing the original libraries and the imported performances in my user still work. If it was just pointing to waveform numbers, then it wouldn´t work if those libraries with the waveforms it was pointing to are no longer there.

Because I don´t see what I could be doing wrong. "library import" is one single function with no options, so what could be done wrong by the user doing the library import?

No options? Really. You can select which PERFORMANCES you wish to IMPORT so that means plenty of options!!!!

Sorry I must have missed the JUNO and JUPITER Libraries you are speaking of... by who?

Doesn't matter. There are options. Let's make sure you know how it is done.

Let's say I want to import some data from an installed LIBRARY. Let's begin by taking a look at what currently is in your USER BANK.
From the HOME screen:
Press [CATEGORY SEARCH]
Set the BANK = USER
Set the MAIN = ALL
You now will see a listing of the items in your current USER Bank.
If it is empty, nothing will appear. If you have Performances in your USER they will be listed... When you import something new it will be added to this list of PERFORMANCES.
If you would like to clear your USER BANK (to start with a clean slate: go to UTILITY > Settings > System > touch the next to the last option "Initialize User Data"

IMPORTING LIBRARY DATA:
Press [UTILITY]
Touch "Contents" > "Library Import"
You will now see a FOLDER for each of the LIBRARIES you have currently installed.
touch the FOLDER to open it and reveal its contents.

You will see the titles of the various PERFORMANCES and a Box next to the Name to indicate you wish to IMPORT that program. That is an option. There may be several pages of data...
Or you can select "SELECT ALL" by touching that box... a check mark will appear next to all of the Names.
Touch the box that says "Import to USER Bank"

Once you execute the IMPORT. Return to the the HOME screen and repeat your CATEGORY SEARCH among the "USER" BANK, the newly imported items will now be listed in your USER BANK... and the fact that you used the IMPORT LIBRARY function to put them there, if you NOW, SAVE as a LIBRARY FILE (.X7L) all of the contents of your USER BANK will be written to a NEW LIBRARY FILE.

Once you have that NEW LIBRARY File, it is your option to keep the original Library as is or discard it (by DELETING it)... what you do will depend on your goal in the first place.

I think you missed one of my posts in this thread because I posted the link to the JUNO and JUPITER libraries. Here again:

https://www.yamahasynth.com/forum/roland-juno-jupiter-jv-2080-for-montage-user-banks-download

and the problem is that not all performances work when I import them. some of them are mute. when importing again, they may work, or may not, it´s not predictable. I tried several times, reerased everything, reimported, and it´s not always the same performances that work or don´t work. Therefore I´m wondering if there is either something wrong with the libraries or if the library import function is not 100% reliable.

As far as a user error, well, yes you can chose wether to import and entire library or just selected sounds. So yes, there is one option indeed, but not really any options where you can make a user error, or what could that user error be? Wether importing the entire library or just selected sounds, what could be done wrong by the user in the process to make the imported sounds mute?

Sorry, why not test it on some known data. There are no Juno or Jupiter sounds made for the Montage that I know of... who made these files. I highly recommend that you try a different Library with some known credentials. This way you can know if it is the data or something else causing your issue. I cannot verify every file on the Internet. Sorry.