Error message - Yamaha FX900

[blackusrattus]

Hello,
My first visit, complete with my first problem.
I have owned a couple of Yamaha FX900 processors for many years one of which started flashing with the replace battery warning. I replaced the battery myself with the intention of reloading the settings from my other unit. via sys exc. However, upon reconnecting I now have an Error message E6 RAM PAGE CHANGE. I have tried restoring facory presets and initialising the ram from some old notes i took years ago but to no avail.
Any advice or help would be greatly appreciated before I cart it off to the menders .

Thanks in advance.