I just bought a Dell Optiplex 7400 All-in-One with pre-installed OS UBUNTU 20.04 LTS. I tried to install dropbox by downloading the 64 bit version from https://www.dropbox.com/install-linux but unable to do so. It says:
"trouble connecting dropbox servers - may be your internet connection is down or you need to set your http_proxy environment variable"
I tried the solutions at "https://askubuntu.com/questions/69434/cant-complete-dropbox-installation-from-behind-proxy" but it didn't help.
Later, I tried to install hplip for my printer hp MFP m427dw which is already there in the network and I have also coonected it with my desktop via usb. I installed hp plugin 3.22.10 by following the instruction at https://developers.hp.com/hp-linux-imaging-and-printing/install/install/index. The printer is working fine but I a umable to connect to the scanner. It says that I reuire to install plugin, which I have already done, and then subsequently says "Network connection not detected" I tried some of the solutions at "https://ubuntuforums.org/showthread.php?t=1507589" but it didn't help.
However, my internet is working absolutely fine. I do need to install Dropbox as all my works are there. Also I use scanner quite often. In both cases, I felt there might be some changes in the network I am required to do as the applications can't connect to the server themselves but I must admit that I am a novish. Please help me with solutions accordingly. I would be really grateful.