This is a minor update that fixes one issue. A user reported on Github that calculation fields, in some setups were calling a function that used PHP’s boolval() function. Unfortunately that function was using an out of date version of PHP and boolval() was added in in PHP 5.5 (released in 2013).
We are releasing an update as, like WordPress we support PHP 5.2 (released in 2006), but like WordPress we recommend PHP 7.0 or later. If you were affected by this, we appologize but we also recommend that you contact your host immediately and ask why you are on an out of date or potentially insecure version of PHP.