I tired adding notes to a company (local installation) and it all seems to work fine. I can add two notes consecutively, I can add more notes to company that already has notes. And this works on both Chrome and Firefox.
Can you please check if the problem occurs regardless of the contents of the note you put in? Try put something short like "Test".
Also, are you getting any javascript errors? This error sounds like a result of an error like that, even errors that are not linked with notes at all.
And can you add new note if you do full refresh of epesi (F5)?
Kind regards,
Arek
