In all the years I've used LyX I've not before encountered this problem and I have not yet found the solution.
I open a .lyx document. Then I select either File->Import->Text, join lines or ctrl-x i (import file) and select the text file I want to insert in the .lyx file. The open .lyx file is closed (displaying the blank lyx screen) and a message box appears telling me that the lyx file already exists and asks if I want to overwrite it or cancel. Is this a deliberate behavior change from the past when the included file was placed in the existing file at the cursor position? I'm preparing a proposal that must be submitted tomorrow to my client so I do need to get this figured out or fixed ASAP. TIA, Rich