Download libgcrypt11_1.5.3 from:
https://launchpad.net/ubuntu/+archive/primary/+files/libgcrypt11_1.5.3-2ubuntu4.2_amd64.deb
Install lib with dpkg
sudo dpkg -i libgcrypt11_1.5.3-2ubuntu4.2_amd64.deb
Install StarUML with dpkg
sudo dpkg -i StarUML-v2.7.0-64-bit.deb