It sounds like the issue you're facing with the "Write to other table" integration could be related to a bug we're currently addressing, but that's fixable by simply creating a new one and setting it up again from scratch.
Here are a few common reasons this might be happening:
1. The table you're linked to might no longer exist.
2. The fields you're referencing could have been removed or changed.
3. There could be more than 6-7 tables linked together, which can cause issues.
Let me know if that helps.