Could not manage the remote device

cndesu

I have TeamViewer 13 on both devices (personal devices) at home. I could not connect to the devices. I tried from both to access the other and I could not access. It says old version. One is Ubuntu 14.04, and the other is Windows 11. Is there any issue if we run on old TeamViewer? Both are old versions so does it matters? Any help would be appreciated. I cannot upgrade TeamViewer because of some libraries on Ubuntu 14.04. I cannot upgrade Ubuntu because of my home automation system which is pretty old and obsolete.