SU2017 export error

Hi
Been using Kerkythea for many years. Just upgraded to SketchUp Make 2017 and plugin stopped working. I have downloaded KTv2.0.19 and SU2KT3_19 afresh today (just in case). I used the Extension Manager in SketchUp to install SU2KT. I have the KT menu buttons and everything seems to work normally until I save the file in the folder location. A *.xml is created BUT it's either 0kb or a very small 5kb. Also the associated textures and geometry folder (that used to be created) doesn't get created. I also don't receive the confirmation window, in SketchUp, that the process has been completed and then asking me whether I want to automatically open KT.
As I said I just upgraded from Make 2016 so my system is the same - Win 7, i7, 16Gb ram, Nvidia 2Gb.
I've been through the FAQ and changed all my component, layer & material naming.
My path naming seems fine to me C:\My Documents\DEBCal\0530 House Behr\Kerk\

Any suggestions?

Don't if it helps but I had another renderer plugin in Make 2016 that was working, which also is not now after installing Make 2017. So wondering if there's possibly a different installation process required or different Folder paths required for Make 2017.
Similar problem btw with the other renderer plugin - doesn't return with a completion window and neither is the final file format created so I can open in the render engine.

UPDATE - opened another project and exporting worked perfectly. So problem is project related. What else should I be checking before exporting?