Ubuntu 20.04: libssl.so.1.0.0: cannot open shared object file: No such file or directory

I ran into the same issue I think (I had the same error message trying to launch RStudio after upgrading Ubuntu from 18.04 to 20.04). Here is what worked for me after reading the following page: https://packages.ubuntu.com/xenial/amd64/libssl1.0.0/download

• Edit the source list sudo nano /etc/apt/sources.list to add the following line: deb http://security.ubuntu.com/ubuntu xenial-security main
• Then sudo apt update and sudo apt install libssl1.0.0.

I hope t works for you too.

I solved my problem with libssl1.0.0 like this:

I opened http://security.ubuntu.com/ubuntu/pool/main/o/openssl1.0/ in my browser and download last version of libssl1.0.0 for my system (for me it was libssl1.0.0_1.0.2n-1ubuntu5.6_amd64.deb) Then I just install it:

sudo gdebi ./libssl1.0.0_1.0.2n-1ubuntu5.6_amd64.deb

I had this problem too. RStudio depends on libssl 1.0.0, while Ubuntu 20.04 distributes the newer libssl 1.1.0.

Here is how to download and install the older version manually:

wget http://security.ubuntu.com/ubuntu/pool/main/o/openssl1.0/libssl1.0.0_1.0.2n-1ubuntu5.6_amd64.deb
sudo dpkg -i *.deb

Hopefully, RStudio will at some point be upgraded to work with the newer version of libssl.