Hi @mortisj, welcome to the forum!
It is possible to downgrade to previous versions (see Downgrading / reverting to a lower version). However, I think there were some database changes made in 2.0.3.2 that make it a little more difficult than normal to go all the way down to 2.0.2.1 beta. 
It sounds like you updated to 2.0.3.3 through the web GUI, which is good because it should be pretty easy for you to try the downgrade the “easy” way. If it works, great - if not, you can just “un-downgrade” and we can try addressing the error directly.