Greetings,
Maybe somebody is facing something similar starting today? When trying to submit a form the following error appears (below). There were no changes to the Base. Also, the same started to happen to an older (4-5 months old) version of the same base. To add more, one of our automations started to act up - We have an automation which fills in 2 "single-select" fields, where the second field is a limited view depending on the first field. This error comes in "invalid item in array cell: foreign record is invalid: row is not visible in column view restriction". Both of these issues appeared out of nowhere. We do have only 1 GB and 10,000 records left in the plan (also tried to making some more to see if that help - it doesn't), but it doesn't seem like it can be an issue.
"Cannot process form submission
Oh no! Somebody made changes to the structure of this form after you loaded it. You'll need to refresh this page to submit your form responses, but when you refresh the page, the information you’ve already entered here will be not be saved.
If you’d like to save anything you've written, please copy and paste your text responses somewhere else (like a word processor) before refreshing the page."