Hi. I use fileWrite to upload file to S3. But I have problems with file names with special charaters (e.g. @). I'm able to create such files by Amazon Console, but ACF 2018 gives me an error: "*Error occurred while performing write: java.io.FileNotFoundException".* I tires to use url encode, html code, but it hasn't helped me. Is there correct method?

I strongly recommend removing all alphanumerics from file names when you're using S3. There's all sorts of quirkiness inside S3 regarding file names, and removing non-alphanumerics will make your life a lot easier.