我尝试按照此处提供的说明安装 openfoam5： https://openfoam.org/download/5-0-ubuntu/
但是当我运行这个命令时：
sudo apt-get -y install openfoam5
下载百分之几后，我收到此错误：
The following additional packages will be installed:
paraviewopenfoam54
The following NEW packages will be installed:
openfoam5 paraviewopenfoam54
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 138 MB of archives.
After this operation, 885 MB of additional disk space will be used.
Get:1 https://netix.dl.sourceforge.net/project/foam/foam/ubuntu xenial/main amd64 openfoam5 amd64 20171030 [80.5 MB]
Err:1 https://netix.dl.sourceforge.net/project/foam/foam/ubuntu xenial/main amd64 openfoam5 amd64 20171030
GnuTLS recv error (-9): A TLS packet with unexpected length was received.
Get:2 https://netix.dl.sourceforge.net/project/foam/foam/ubuntu xenial/main amd64 paraviewopenfoam54 amd64 0-3 [58.0 MB]
Err:2 https://netix.dl.sourceforge.net/project/foam/foam/ubuntu xenial/main amd64 paraviewopenfoam54 amd64 0-3
GnuTLS recv error (-9): A TLS packet with unexpected length was received.
E: Failed to fetch https://netix.dl.sourceforge.net/project/foam/foam/ubuntu/dists/xenial/main/binary-amd64/openfoam5_20171030_amd64.deb GnuTLS recv error (-9): A TLS packet with unexpected length was received.
E: Failed to fetch https://netix.dl.sourceforge.net/project/foam/foam/ubuntu/dists/xenial/main/binary-amd64/paraviewopenfoam54_0-3_amd64.deb GnuTLS recv error (-9): A TLS packet with unexpected length was received.
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
我的操作系统是 Ubuntu 16.04 请问有什么问题？ 解决办法是什么？