Fatal Error when saving custom page

Ok, whilst building a site, a page refused to echo any custom fields. No idea why it’s one page in particular but I can say that it’s due to the above fatal error.

If I remove the [] from that line in api.php then the page shows but only with the first letter of a string displaying.

Downgraded to 4.2 from the CFS GitHub page and still getting a problem. Don’t want to go too far back incase it breaks my field groups.

Do you have any thoughts / solutions?

Thanks,
Jack

I should also mentioned this that i’m getting this when visiting the page in question on the front-end and also when saving it in the back-end. It’s the same error both times.

When I save a page, the screen goes white and the above is the only error in the log.
The page has saved just fine though.

Hi, two fields on your edit page with the same name maybe?

Yup, that was it! Thanks.
I presumed (for some reason) that if a field was under a different tab field you could do this but I think it’s because I was thinking of tab fields like loop fields.

It raises an useful point – is it possible to integrate better error handling of this? Or automatic field renaming should a field with the same name already exist? Or even a warning that there’s already a field with the same name on the page?

Thanks,
Jack