Audio disappears in Quizmaker

The Quizmaker audio disappears even when no changes are deliberately made to a presentation. Is this because the folder containing the files was moved to a different part of the directory structure? How can I use the questions and keep the audio in them? 

Here's a log below of what happens.

I recorded audio directly into Quizmaker. I kept the quizzes in the same folder as the PowerPoint and Articulate files, copied the folder to our network drive for backup, then copied the folder back on my C: drive to work. The contents of the folder on C: are unchanged and include the quizzes,  PowerPoint and Articulate files - but the folder is in a different place in the directory structure on C:

Previewed Slide 3 and 4 (question on slide 4) – audio played. Exited w/o saving. PowerPoint and Articulate are redated from 4/28 to 9/2;  there is a new Articulate file with name ending “-old”.  

Re-opened presentation and previewed Slide 4 (question).  Audio played. Exited w/o saving.

Re-opened presentation and Quizmaker. Selected question in Slide 4 and clicked Edit. Saw this message: Unable to access quiz LTBI Treatment Options for Case1.quiz.  Please locate this quiz. Clicked OK, Cancel, and exited w/o saving.

Re-opened presentation and Quizmaker. Clicked Add Existing. Quizmaker went to a folder where I'd worked earlier in the day: C:\Users\jkanouse\Desktop\LTBI HIV Review Posting 0825\Lesson 5. Navigated back to folder with presentation and selected Slide 4 question It was inserted as a new Slide 2. Clicked to the Slide 2 question. In preview of the question, there was no audio; in preview of the group, there was no audio. Heard clicks when selecting response options, so sound worked.

Re-opened presentation and previewed Slide 4 (question). Audio played for Slide 5 question (was Slide 4). Previewed Slide 2 (newly inserted copy of Slide 5 question) but there was no audio, only response option clicks. Exited w/o saving.

Re-opened presentation and opened Slide 5 question  for editing in Quizmaker. Previewed Slide 5 but there was no audio, only response option clicks. Exited w/o saving.