Ubuntu 16.04 and php7.0

Ubuntu 16.04 comes with php7.0, and Front Accounting requires 5.x. You can, in fact, install the 2 versions of php alongside each other, and you can set it to default to php5.6 for Front Accounting (but you can still switch to php7.0 if you need to for something):

In a terminal:

digger@computer# sudo su
root@computer# add-apt-repository ppa:ondrej/php
root@computer# apt-get update
root@computer# apt-get install php7.0 php5.6 php5.6-mysql php-gettext php5.6-mbstring php-xdebug libapache2-mod-php5.6 libapache2-mod-php7.0 php5.6-curl php5.6-gd php5.6-mcrypt php5.6-xml php5.6-xmlrpc

Installing both php5.6 & php7.0 was clean in my case: no complain of issues, etc.

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To switch from php7.0 to php5.6:

# For php in web apps (Front Accounting)
sudo a2dismod php7.0 && sudo a2enmod php5.6
sudo service apache2 restart

# For php-cli in the command line
sudo ln -sfn /usr/bin/php5.6 /etc/alternatives/php
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To switch back from php 5.6 to php 7.0 you need to do two things:

# For php in web apps
sudo a2dismod php5.6 && sudo a2enmod php7.0
sudo service apache2 restart

# For php-cli in the command line
sudo ln -sfn /usr/bin/php7.0 /etc/alternatives/php
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You can also quickly check which version you are currently set to by typing in a terminal php -v. Also please note that the new version of Front Accounting will be compatible with php7.0.