Thank you
The issue only appears to present on older version of IE. To amend could you try removing the following from your templates styles.php (../templates/j51_nocturne/php/styles.php)...
Line 222
background-image: url(data:image/svg+xml;base64,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); /* gradient overlay */
Line 242
-ms-filter: "progidXImageTransform.Microsoft.AlphaImageLoader(src='<?php echo $this->baseurl ?>/<?php echo $bgimagefile; ?>',sizingMethod='scale')";
And also the following from your templates nexus.css (..templates/j51_nocturne/css/nexus.css)
Line 153
filterrogidXImageTransform.Microsoft.gradient(startColorstr='#331b1b1b',endColorstr='#b21b1b1b',GradientType=0);
Line 772
filter: progidXImageTransform.Microsoft.gradient(startColorstr='#ffffffff', endColorstr='#ffe5e5e5', GradientType=0);
Line 776
filter: progidXImageTransform.Microsoft.gradient(enabled = false);
Ciarán