Rendering my freshly created diamond gives no good result I am a beginner at Blender and very enthusiastic about the enormous possibilities. It is a flood of options.
I started with the creation of a sparkling diamond as a part of a logo for my daughters business. I found a perfect youtube tutorial and succeeded making the diamond. After making the diamond I let turn the animated diamond. It looks very realistic! I am proud at myself! But...
When I start rendering the diamond animation or rendering the image I got a very strange result. See my image from the result. I tried in my opinion everything but no result.
I run Blender on my iMac Pro.
Who can help me?

The image shows the diamond animation in layout. It was constructed using a youtube video (Making Awesome Diamond Shader in Eevee - Blender Tutorial by VFX Mastro).
It looks for me as a perfect diamond!
Render animation shows on the left the red diamond output using the Evee engine and the output setting on the right side.
Purple = a linked image is not found.
so as @frederik wrote, it's something related to a material of the world (HDR image) that is not found by blender