Hello, if the new version of the miniclient is not working properly for you, then please try to redownload it. You can download it at the following site. Some players prefer using an older version of the miniclient, which can be found via the playerbase, please let me know if you wish for it. Otherwise, is browser working correctly for you? From what I have found, this error typically occurs due to an issue with the downloading process, redownloading it should help, after ensuring all previous miniclient files are entirely deleted from your computer.

Do you have any antivirus software installed?