1) If you have not upgraded SteelCentral Portal yet to version 3.6.0, please contact the Global Support team or Professional Services team before upgrading from 3.5.x to 3.6.0 for assistance to mitigate this issue.
2) In case you already upgraded SteelCental Portal to version 3.6.0. you can re-upload the same images to the panel in question, which recreates the “dialogImages” directory, whit the image files of interest and allows the dashboard to work again.
NOTE: Once you upgrade to 3.6.0, the images are lost, and there is no way to work around it besides uploading all the images. We are working to fix this issue BUG#: PORTAL-607.
Steps for re-uploading the missing images.
a) In the Dashboard, -> Click Create-> Cancel the default window that comes up.
b) Then Right-click and select "Create new Auxiliary Panel"
c) Under "Panel Type", select Static Image
d) Give it a Title or keep the same if it's an existing Panel.
e) Under "Image Type", select "New Image"
f) Then Download/Select the image after selecting "Choose File".
g) Click "Create"
h) Then Save the dashboard