Thanks, unstalling zotero correctly seems to have done the trick. Now Alt-F9 working. Panic over. To be clear it wasn't Zoteros Word plug-in that broke all , but a variant of it that someone on that forum was writing (snd still debuggig) to up it functionality (double linking of refs). It searched for fields and changed them, which mucked up a few things. Panic over , back to normal again - now just have to keep writing a thesis content.

THANKS