Ford Ecosport keyless start problem

[Ecosporter]

Hi, my wife’s Ford Ecosport doesn’t seem to recognise the key. We got Greenflag out and they put the fob next to the steering wheel and it worked but now that won’t work either. 

We changed the batteries in both keyfobs and they open and close the doors but when we push the start button a red padlock in the dash flashes and all sorts of errors come up.

someone said it could be to do with the grounding in the battery? 

Please help we have tried to find a local mechanic but with no joy 

Thank you