Fatal Error requires a license file

You probably have SEF Advance for Joomla 1.7 while you use K2 sef_ext.php extension for Joomla 1.5.
You will have to remove it, there is still no extension available for Joomla 1.7. K2 has only recently been updated for 1.7. I will be looking into building the new extension for 1.7 K2 soon.

Ah I see.  Do you have an estimated time until this is ready?  I can't really use this product unless it works with K2

Will try to do it in next few days.

Ok I will hold tight, please could you mail me when it's done? 

Can you please mail me with your site access info?

Have done so, much obliged for your assistance