Cropped screenshots are pretty useless. We need to see the layer structure, the modified properties of the layers that are giving you problems, and a detailed workflow description.
Blend a layer indicated you are using the C4D rendering engine and you have a standard layer that you want to bend. Your screenshot doesn't look like that is what you are doing.
Vector layers disappearing when you suggest that you may have pre-composed the vector layer and then scaled the pre-comp. That problem can be solved by collapsing transformations.
There are just way too many different ways to end up with a cropped layer problem for anything more than a guess. Select the layer or layers that are giving you problems, press the U key twice so we can see what you have done to the layers, then post a screenshot of the full UI so we have some idea what is going on in the comp.