When trying to upload a file from android from the top right "+" button > upload files > browse files in other apps > pick any app > select the file and upload it. It throws the next exception:
AsyncExecutorError: AsyncTask execution error at _IsolateThread#7 --Cause: type 'Null' is not a subtype of string
this won't work (it will be correctly uploaded) if you select the file from any other app source (e.g. gallery) > share it > S3 drive > upload here
