once in a while it occurs to me that older Cinema 4D Files with Octane Materials won't open. It loads forever, gets stuck, c4d freezes. Reason for that are Cinema 4D Gradients used inside the shader tree. They are supported, you may use them, but sometimes it can be problematic. It seems only to happen with older scenes.
Maxon Support told me there would happen a loop in correlation with the Substance Module of Cinema 4D, even when not using Substances or Substance Assets inside your scene. The Substance Engine is necessary to "walk through the shader tree" via Octane, to quote Maxon Support. Therefore, in case you have the same issue, I present to you my Solution:
You could try it with Octane inside the plugins and try to find the gradient used in the materials. I'd rather suggest using the c4d function "Material Exchanger" to get working materials with the same name from other files, or, sadly, delete all the materials and replace them. One trick might help you: If you create new materials and import/copy-paste/merge them into your file with the problematic materials, Cinema 4D allows to replace single materials by drag&drop the new material onto the old one while holding the ALT key.Go to you Cinema 4D directory (depending on version and operation system the location may differ) and find the folder "modules" which is filled with ".xdl64" and ".cdl64" filetypes. Find "substance.cdl64" and delete or remove it from this directory. I removed "c4doctane" from my plugins directory so there is no room for errors between Octane and Substance for sure. Start Cinema 4D, it might load a little while longer than you are used to, yet it will open the file properly.
In case that's too much work, I'd kindly ask the Octane Support to either find or remove the Materials for you. I found out which material caused the problem by contacting aoktar via forum thread and now am able to remove every instance of it in around 64 scene files myself.
