Hello sky,
Does EmEditor display the same dialog box even if you open the entire file (or without Large File Controller)?
If the dialog box appears only when you specify a filter, then this might be a bug. In this case, would you please send me a sample file so that we can reproduce the issue?
If the dialog box appears both when you open the entire file and when you specify a filter, this is an intentional behavior, and cancelling the dialog box will close the file.
Thanks,