Whilst a relative novice, I’ve been using Eagle freeware for some years now – quite happily using Library Loader.
Have continued in this vein since renting Eagle Premium using:

to download specialist component ECAD models from SamacSys, and store them in a local library named SamacSys_Parts. These were always immediately accessible, off-line, without having to reload them every time.
Yesterday I possibly made the mistake of using Eagle’s inbuilt system

This had the unfortunate side effect that it seemed to proceed normally, but when I looked for that library in the pull-down ADD feature, the library no longer existed.
I invoked the Library Manger – which shows this library – selected it and clicked “Use” - after a long and tedious update – seemed to work.

When I then went back into “ADD”, the part headings ALL came back – but no symbol, nor footprint showed up.

When I then proceed anyway, I get the following:

What to do – what has happened – why did it happen, without any warning - how do I rectify this please?
I'll add this - I tried using the Library Loader to re-load one or 2 of the parts - it came back with "part already exists in library, do you wish to overwrite?" or similar words - I answered YES. But - the library was still disappeared when I tried ADD - and when I went through the laborious process again, the re-installed part heading showed, but still no symbol or footprint.
Just 2 notes:
- I wish to continue to work off-line, so need the libraries local.
- I do not wish to go on-line, and re-download the library EVERY time I open Eagle – as I access this repeatedly from time-to-time between other jobs – the data costs would cripple me.
Hope someone can help please, as I was about to submit a prototype board for manufacture – just wanted to change 1 inductor for another - when this happened.
Disgruntled
Ian Thompson