The debian package has been built on/for on Debian 7.

The install procedure involves the following steps:

sudo apt-get install apache2 postgresql  [to get dependencies that need to be configured beforehand]
sudo dpkg -i tissuestack_1.5_amd64.deb [which will fail, so don't be surprised!]
sudo apt-get install -f [which will deal with the causes of failure in the step above]

alternatively you can install gdebi (apt-get install gdebi) and run: 'sudo gdebi tissuestack_1.5_am64.deb' which will save you the above hassle

ATTENTION: 
There has been a post/post-uninstall script mistake such that if an older tissuestack version is installed
a reinstall or alternatively a remove of the older version prior to install is necessary.
These errors should not occur any more for versions higher than 1.7.