Cannot buy from signs after update to 1.14.4

[runelynx]

Hiya,
I am updating from 1.13.2 to 1.14.4 today and moving to your version of SignShop at the same time. If I left-click a wall sign, it correctly confirms the pricing. But if I right-click, I get a console error. Can you please let me know what i can do to resolve?

[runelynx]

I see what the problem is; your version of SignShop is not loading any of the sellers from sellers.yml. It's treating them all as invalid.

My file starts out like this...

And your version of this plugin makes it end up looking like this:

Is this version of SignShop not compatible with sellers.yml files from previous versions?