Hello,

I believe there's an error in the stringToLower filter @ line 61:

if (array_key_exists('encoding', $options)) { $this->setEncoding($options); }

And definition for setEncoding is: /** * Set the input encoding for the given string * * @param string $encoding

So $encoding must be a string, and it gives an error ("The given encoding 'Array' is not supported by mbstring") if you give an Array, which you obvious do.

So line 61 should probably be: $this->setEncoding($options['encoding']);

This also applies to StringToUpper, and maybe others.