Header won't update properly

Am in the html editor section of my site and just want to drop a bit of html script into the head tag. Get the following message - when I hit the update button it finally responds with this message. Plus it didn’t implement my change. Any ideas that can help?
Message says:
Something went wrong. Your change may not have been saved. Please try again. There is also a chance that you may need to manually fix and upload the file over FTP.

Hi @christ123,

Can you explain the issue in a bit more details, I didn’t quite understand the issue. Where exactly you’re editing, can you explain that using a screenshot, so that it is best to understand.

Let us know,

Thanks,
laranz.