Hi Mitchell, Just need to confirm a couple of things, are you using Hosted or a desktop version of Reckon Accounts? Just asking because you've mentioned Hosted 2018 however this edition hasn't been released yet and also, as its cloud based, there is no uninstall/reinstall process.
Can you confirm? Also, can you let us know which operating system you are using?
Where does this error appear? ie. opening the program itself or opening your file?