Hi,
changing a gradient to linear/radial deletes not only the connected vertex map node, but the vertex (color) node on the object also.
This is not unduable.
Try the attached test scene and open the material, either in Node Editor or in Cinemas material editor. Change the Gradient to linear or radial and have an eye on the tags of the object plane in the object manager, especially the vertex color tag. It disapears at the same time as the vertex map node when it gets replaced, the material changes in LV and Active Object Manager also shows, that the tag is gone. As said: this is not undoable.
To get there I simply painted the vertex color into the tag, opened a new material in the node editor, made a vertex and a gradient node and linked all together. Then I switched the gradient for mistake. One can start the LV to see the changes there as well.
Please tell me if you need more info to reproduce as well.
Hope it helps, and thanks.
This is tested with R19.053 + Octane 3.08 RC11 and R18.057 + Octane 3.06.2,
Win 10 Pro, GTX 1080, 4K monitor, 96 GB RAM, Nvidia 388.71*. Standalone 3.08 RC 1
and also by some other C4D users with different machines.
No response in the log window.
*391 also, but it is a mess to install this with win 10.