RAG Corpus cannot be deleted due to running operation

[Lennard]

Hello, 

I am newer to GCP and recently started following the guide to setup a RAG corpus using vertex AI (https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/rag-api#python) 

I created a corpus and started import files into it but after a while the process timed out. Now I cannot delete the corpus or start over because there are running operations on the corpus. 

Is there any way to cancel the operation? Using an example url to cancel the process using curl  only throws a 404 error. 
i.e projects/{id}/locations/{location}/ragCorpora/{corpora_id}/operations/{operations_id}:cancel

Thanks in advance