Documenting specific case of Coreix where I have my own server (but don't really know how to do tech side of it).

Install fails with general error.

Solution - edit .htaccess and create a php.ini in the same directory.

You do not need to edit any other files as the system will look for a php.ini automatically.

A hash is a comment - mainly used to allow plain english explanations of what the code does, and also used as quick way of telling the system to IGNORE lines of code.

To Solve

Your .htaccess with Drupal includes something like this...(note - the php memory is a change I made to it before uploading so default .htaccess do not have this line)

# Override PHP settings that cannot be changed at runtime. See
# sites/default/default.settings.php and drupal_initialize_variables() in
# includes/bootstrap.inc for settings that can be changed at runtime.

php_value memory_limit 256M

# PHP 5, Apache 1 and 2.

php_flag magic_quotes_gpc off
php_flag magic_quotes_sybase off
php_flag register_globals off
php_flag session.auto_start off
php_value mbstring.http_input pass
php_value mbstring.http_output pass
php_flag mbstring.encoding_translation off

Coriex looked at the Apache log files and said that three values were not liked and needed moving to a php.ini file. Your system might want different vales in the php.ini, and perhaps it would be worth trying moving them ALL to the php.ini. But I am not an expert

EDIT .htaccess to comment out the troublesome lines. So in my case it becomes

# Override PHP settings that cannot be changed at runtime. See
# sites/default/default.settings.php and drupal_initialize_variables() in
# includes/bootstrap.inc for settings that can be changed at runtime.

#php_value memory_limit 256M

# PHP 5, Apache 1 and 2.

php_flag magic_quotes_gpc off
php_flag magic_quotes_sybase off
php_flag register_globals off
php_flag session.auto_start off
# php_value mbstring.http_input pass
# php_value mbstring.http_output pass
php_flag mbstring.encoding_translation off

AND

In your hosting file manager create a php.ini file in the same directory as the .htaccess one

php_value memory_limit 256M
php_value mbstring.http_input pass
php_value mbstring.http_output pass

It is literally just those lines. It doesn't need any php start/stop tags or code.