Magento 1.9.2 and php7 - image upload error

http://php.net/manual/de/migration70.incompatible.php https://wiki.php.net/rfc/uniform_variable_syntax

Due to uniform variable syntax the code is now interpreted strictly from left to right.

The line

$params['object']->$params['method']($this->_file['tmp_name']);

should be

$params['object']->{$params['method']}($this->_file['tmp_name']);

You can find a overview of all files to edit in this answer.

In Addition to the answers above, don't forget to check the file:

\includes\src\Varien_File_Uploader.php on line 259

Replace

$params['object']->$params['method']($this->_file['tmp_name']);

with

$params['object']->{$params['method']}($this->_file['tmp_name']);