I spent quite some time trying to fix this problem but cannot find any clues (sorry, I'm php beginner  ).

Normal !roll function works great but when item reference is added, verification blob output looks like this:

::: Roll Verification: 1 :::
Roller: Maureen
Time: 0 seconds ago
Target: <a style='text-decoration:none" href='itemref://3770720/3770720/80/f58505ab:bdca28a6:16851a1a:ff8efdc4/f58505ab:bdca28a6:16851a1a:ff8efdc4'>[Blade of the Crowned Serpent]
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Range: 1 - 24
Result: 8
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Item name itself is colorized properly but obviously can't be clicked. I'm using 0.6.8 stock Roll.php module. Any help would be greatly appreciated.

What was the command you gave to start the roll? When asking for help, you should always provide a way for people to re-produce the problem you had.

!roll 1 24 [Blade of the Crowned Serpent]