3822730 - Why did the user get the Error: "Concur Imaging Service Not Available" when hovering over a receipt image?

I cannot see the receipt attached to an expense item. When hovering the cursor over the receipt image icon the following error message appears: "Concur Imaging Service Not Available. Image Server Error". The same error shows if I attempt to click and view the receipt. I tried to delete the image but was not able to do so. What caused the error and how can I fix this?
 

An error is displayed when viewing a receipt image , KBA , CON-MOB , Concur Mobile , CON-CA-ADM-USR , User Administration , CON-EXP-ERT , E-Receipts , Problem