The following error message appears while exporting a voice memo, even though the voice memo can be played on the device:
"The file or folder does't exist: /Recordings/filename.m4a"
When you crop a voice memo on device, the voice memo file is sometimes moved to a different location.
Cropped voice memos can be found in the File System view inside of the /Media/Recordings/filename.composition folder. Simply replace filename by the name of the file mentioned in iMazing's error message to locate the file, here 20160815 092438 for example. Note that the audio file you'll find in the .composition folder will not be cropped.