facing this grid issue: Type RecordType constructor passed 17 fields, but expected 50 fields

Try this,
Open LIS Supplier Record Type and manually full sync.
Open record type and fix list grid columns data.
As i can see banner on top of your screenshot seems to be a upgrade issue please wait meanwhile appian fix it.

It is not a code issue but there seems to be an issue in the Appian Community Edition as the same error is shown in all interfaces having recordData configured as data for gridfield(). Other grid having local variables with list of record Types are working fine though! 

Looks like recent upgrade has caused some issues. Suggest you to drop email to communityedition@appian.com informing them about the issue so they can look into this!

I am facing the same issue its not only at the interface layer even the record list of newly created record type is throwing same error. So it must be some upgrade issue.

Could you please more specific about the resolution or it would be great if you help out what to exactly. Even I tried to troubleshoot but no issues shows up. But unable to view any record type record lists or interfaces.

In some records and interfaces I am encountering the same.

Currently we don't have a solution for this until appian fix this, But recently i had created a personal worrkspace account using my secondary ID, with Germany server, Everyhing is working fine(didn't see any issues), if someone looking to have hands-on, you can try germany server, but understand, there will be latency, unsupported features etc. This is one of the solution, if you want to start from scratch/explore.

Happy to help if anyone needs guidance for creation.

A good workaround for time being!