Why does Audacity have to import files every time at start up. It’s about a 10 minute wait period
Not a Windows user but this shouldn’t happen.
What version of Audacity and what version of Windows are you on?
So Audacity was redesigned with 3.x.x to remove the archaic? many files in many subdirectories structure. It now has a unified file structure - everything is contained in one single .aup3 file.
At that time the designers decided they only wanted to support one system going forward, so the old .aup/_data structure is now obsolete. If you have an old .aup file, that must be “imported” which converts it into the new .aup3 format.
Fortunately, if you care to save your new .aup3 file, that will frequently take only a minute or so, and the next time you open it (the .aup3 file, that is), is should open fairly quickly - even faster in 3.1.3 that in prior 3.x versions. 