To: hit_ny
Thank You for responding to my inquiry. In response to your questions, the drive letter for the external USB drive is fixed and is drive F:. The library definition files are also on the external drive F: and all are present. I have several libraries and all but the default are defined on the external drive. When I start MC it attempts to initialize the last opened and active library.
After further experience with this setup I can relate the following. The problem occurs when the external dirve has not been initiated and hence MC can't find the library files. This is an error on my part and it is now clear that this is the way this happens. However, I still feel as though MC needs improvement in this area as externally defined libraries may very well be an important future implementation, what with the explosion in mobile everything. Let me explain what happens in my scenario...
I start the laptop without the external drives. Without thinking I start MC and it can not find the library. It must see that a library of this name has been defined. I'm thinking this because rather than tell me that no such library exists, which is what I would have expected, it presents the now dreaded import files to your library window. Apparently it will proceed to redefine and populate the library itself.
Realizing what I have done I try everything I can think of to correct the situation. First, I initialize the drives, I cancel the import files into the library window and in the menu FILE/Library I select the default library. It should be defined on C: and be in its pristine condition (i.e. no changes since MC installation). After that I use the FILE/Library menu to reselect the library on the external drive. I am doing this in hopes that the internal data structures in MC might be cleared and now with the external drive online MC will be able to find it. No luck.
My next try was to shut everything down, MC, the external drives, the computer, everything. Then restart. Only this time I remember to initialize the external drive before starting MC. To my surprise MC still can't find the library. Something internal and recorded in the library data structures has logged that this library does not exist. Not even restarting everything in proper order will not recover the "lost" library. Up to now the only way to recover the library is to reimport all the files. This is a real drag when the library contains some three thousand files. There is one other option and it is my current work around and that is to backup the library with every session and if I goof and start without the library drives initiated, restore the library.
I think that the developers could improve this and make it much more fault tolerant. After all, in the mobile world, starting your system without all the external drives initiated is not uncommon. Why, if a library has been defined but MC can't find the definition files, doesn't MC simply present an error message which says, "Library not found." and then provide a recovery path. That would allow for those of us in the mobile computing world who absentmindedly forget to initialize all of our external drives. Thank You.