Problem Description
In ServiceDesk Plus, square boxes appear instead of icons for text styles, fonts, bold, italics, and image insertion in the mail editor screen. This occurs because the inline image (icon) files in the application are missing or corrupted.
Solution
You need to reinstall the missing icon files by following these steps:
1) Download the required file.
Download the images.zip file from the following link:
2) Unzip the ZIP file.
Unzip the downloaded compressed file and extract the image folder inside.
3) Copy the folder to the correct directory.
Directory for Windows:
C:\ManageEngine\ServiceDesk\inlineimages\ze\
If the .ze folder doesn't exist, you can create it yourself.
Copy the entire image folder into it.
4) Restart the application.
Windows:
Services → ManageEngine ServiceDesk → Restart
5) Check
All icons (bold, italic, font, image, etc.) will become visible again when you reopen the email template.