this is maybe a silly question. But my original submission was sent back for technical corrections. I went to check the status in Editorial Manager and clicked 'Edit Submission' just to see the files I had submitted; my intention was not yet to re-submit the manuscript. Then, when returning back to the main menu, I noticed that my submission was moved to 'Incomplete submission' from 'Submissions Sent Back to Author'. Did I do something wrong? Will the editor still notice that I re-submit the manuscript, or did the process started all over again? :( Will the co-authors also be sent a note when I have done the submission?
It just means you've started to edit the submission but have not resubmitted it. The status is similar to if you start filling up a job application but have not input all the necessary details, so the system does not register the application as submitted. Viewed another way, if a system allows you to save your application with a 'save as draft' button, then after you click that button, the status is the same as 'incomplete submission'.
So: nothing to worry about, keep doing what you're doing, and when the paper is ready for resubmission edit the submission again and resubmit. Will the editor notice? If they are looking at the journal, yes - the current status of each manuscript is prominently displayed in Editorial Manager (but they are not likely to do anything, since this status indicates that the ball is in the authors' court). Can the process start all over again? Probably not. Even if you submit the manuscript as a new manuscript rather than a revision, Editorial Manager should flag your manuscript as a duplicate. The editor should then be able to merge the submissions. It's possible an editor inexperienced with the software will not know how to do this, but the publisher should be able to help.
"Incomplete" is there to remind you that you did not submit.
Did I do something wrong?
Will the editor still notice that I re-submit the manuscript,
Not until you complete the resubmission.
Will the co-authors also be sent a note when I have done the submission?
Not before you complete the resubmission.