Opencart Denzi Template landing page error

I get this error code with this theme and would like to know if anyone knows how i can get it removed/solved permanently.

Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15

Only the Theme Developer would possibly able to assist, who else should know about ?!
Ernie

PS: But this site is full of errors, to start with:
Examples:
Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15Notice: Array to string conversion in /srv/disk11/2110261/www/alphacomonline.com/catalog/model/tool/image.php on line 15Notice: Array to string conversion in /srv/disk11/2110261
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<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=">
<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=">
<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=">
e.t.c.!
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