HI. I have created Annotation with image viewer. It has few problems for saving annotations.
In word documents Annotations sometimes saving and sometimes not saving.
Excel file also have some problem.
i have shared the sample application.
https://1drv.ms/u/s!Ashw7CN5fQm2lW4NmXZAggQQinSq?e=bWTXL5
This issue is already under investigation here (Annotations sometime saving and sometimes not saving in Word/Excel documents with HTML viewer).