An update on this issue for all others who are facing this.
I received a couple of replies to my support request from Webflow. I am pasting the relevant snippets here :
Reply 1 :
Typically, this issue stems from:
- the use of a Select Field, Radio Field or File field within the form that is connected to the flow.
- using a Phone or an Option / Select field in the CMS collection being targeted by the “Search for CMS items” action block.
Our team is aware of the second issue above and a fix is being investigated.
In case the Phone or Option / Select fields are being used in the CMS collection being targeted by the flow, could you please;
- remove those fields (or replace them with plain text fields)
- publish the flow as well as the site
- try to send another form submission to determine if the flow works as expected
In my reply to the above I told them that the above scenarios don’t apply to us and we are seeing this same error on a new simple email form, new collection and new logic. We are also seeing this on a new account. I also pointed that others are also seeing this and pointed them to this thread.
Their follow-up email stated the following :
am sorry that you had to wait longer than expected for a reply. We are working through a backlog of requests and we’re hoping to improve our waiting times soon.
I didn’t mention this earlier but I wanted to assure you that I’ve already escalated this to the Logic team, and I hope to gain more clarity on what the underlying issue could be.
At this time, the alternative would be to use a task automation service like Zapier which integrates with Webflow to “listen” for form submissions and then send that data to a destination of your choice. Here is a tutorial on setting up a similar workflow — Zapier Integration | Webflow University.
Once I getting more information, I will be reaching out with a further update.
While Zapier is an option, we are not comfortable with this option. First we would need to pay for another automation and this seems like such a fundamental feature that it just feels wrong to involve another subscription service to do this. Second, another service would come with its own nuances plus another point of failure.
In our case we already are using AWS in the backend for storage and other things, so I went ahead to write an AWS serverless function that uses the Webflow CMS API. The API reference is at Introduction
You don’t need a serverless function and could code this on any backend web server using anything you are comfortable with. But you can’t code this on the frontend, you need a backend server, or in our case since we were anyway using AWS Serverless for other tasks, it made sense to write a serverless function that updates a collection item with a value using the Webflow CMS API.
And I am happy to report that this works 
At this point I don’t know when Webflow will rectify this in Logic. So it seems its either Zapier or write your own code like we did
If you need any further help please feel free to contact me directly on my mail id below. I shall update here in case I hear further from Webflow.
Regards,
Jatin
jeetu.golani@gmail.com
