Channel export fails when Grade A dataset index is missing

[VolhaBazhkova]

StatGPT Backend version

latest

Short description

What steps will reproduce the bug?

1. Create any valid Channel
2. Don't add Grade A dataset
3. Export the Channel

What is the expected behavior?

Export of the chat should be successful even if there was no Grade A indexing

What do you see instead?

Error appears:

Additional information

No response