OG Data Entry - Unable to Save Data Entry

Hi all, 

I created a quicklist for soil proportion and particle size

 

When this quicklist is used in OpenGround Data Entry, an error occurs where the user is unable to save the data. 

If the entry is deleted, the data will be saved normally and the error disappears. 

Here are the details for the header if needed. 

Edit--

I removed the quicklist, and now the header is just a string (longtext). The error still occurs. This only occurs when I try to enter data for the Particle Size header. 

Edit2--

Now I have deleted all the data in all project within the header, in an attempt to reformat the header back to a picklist. It was originally a picklist in the USDefault config pack provided to me. Despite all fields being empty, the header cannot be revised or deleted. I suspect that something is broken now with this header.

Thanks,