Using the Action > Assign Review Rules option in GIFTS 6.4 causes an error. Please do not use this option as it is non-functional and was not intended to be included in GIFTS 6.4.
Also, within the Administrator Module, if you go to Setup > Reviewers > Review Assignment Rules and create a New rule or edit an existing rule, there is a related option called Apply Rule to GIFTS/MyGIFTS. This box is checked by default. If it is checked, and you use the Action > Apply Review Rules option in GIFTS, the error will occur. If it is unchecked, and you use the Action > Apply Review Rules option in GIFTS, you will be prompted with a message saying "No Review Rules are available to be applied to the selected Requests."
NOTE: In step 3 of creating a Review Rule in the Administrator Module, there is a visible Committee button. Clicking this button will also cause an error. Click OK to close the error message prompt.
These options will be removed in future releases of GIFTS. No resolution is scheduled for GIFTS 6.4.