Re: Upload PDF files/proper encoding

A 'path/conflict/folder' error like this indicates that the upload failed because there is already a folder at the specified path (not a file). The "overwrite" mode will only overwrite files, not folders.

When uploading a file, e.g., using files_upload, you need to specify the whole path where you want to put the uploaded file, including both any parent folders as well as the filename and extension. 

So, for example, the value you pass to the "path" parameter should look like "/folder/file.ext", not just "/folder".

In your code, you're passing in a variable named "folder" as that "path" parameter. The value of that variable isn't shown, but based on the name it sounds like it's just the folder path, not the entire desired file path. If that's so, you'll need to update your code to construct the entire file path and specify that when uploading.