Video files seem to become corrupted when I adjust speed

Question

Hello,
I have started editing a new project, and am experiencing a familiar problem that I have encountered in the past, but which was never really resolved. I'm not very technical, so apologies if my description of the problem is simplstic.
The problem is that after making certain edits in the Project window, I find that the entire project has some how become corrupted: i.e. every single clip becomes impossible to edit - I can't spool through the clips and view them in the screen by dragging my mouse cursor over them, and I can't even delete the clip whose edit seemed to result in the corruption.
If I leave the project to go back to the project library, it is now impossible to re-enter the project. The words "edit project" in the button at the top left become grey. I find that the most common cause for this problem is whenever I attempt to adjust the speed of a clip, or reverse it. Is this a common problem with a simple solution?
I have come up with a makeshift solution, which is far from satisfactory, but does sometimes help: I remove the file in the iMovie Events folder in Finder that contains the clips that I can no longer edit, and open up iMovie. The event library in iMovie will now be empty; I replace the events files back into the iMovie Events folder in Finder, then import a random clip into iMovie. The random clip is imported into a seprate event of its own, and the original file that I had put back into iMovie Events reappears simultaneously. Sometimes when I do this, the clips in the Project library are editable again, but not always.
However, I would far rather that the programme simply processed my edits without corrupting the project. Is anyone familliar with this problem, and does anyone have a solution. Thank you very much in advance.

Answer 1

There are several likely sources of corruption, and video card would be far down on my list of possible suspects.
The transfer from camera card to hard disk is the most likely place for problem, either the card reader or USB cable can go bad. Another likely source of problems is the computer's hard disk is starting to fail. The camera card itself may be bad. And lastly, the memory in the computer may be malfunctioning.