Magento Invalid Category error diagnosis

My problem is similar to these: [login to view URL] [login to view URL] here's the exact error: Invalid category Trace: #0 /home/public_html/app/code/core/Mage/Catalog/Model/[login to view URL](182): Mage::throwException('Invalid categor...') #1 /home/public_html/app/code/core/Mage/Catalog/Block/Product/[login to view URL](86): Mage_Catalog_Model_Layer->setCurrentCategory(Object(Mage_Catalog_Model_Category)) #2 /home/public_html/app/code/core/Mage/Catalog/Block/Product/[login to view URL](129): Mage_Catalog_Block_Product_List->_getProductCollection() #3 /home/public_html/app/code/core/Mage/Core/Block/[login to view URL](642): Mage_Catalog_Block_Product_List->_beforeToHtml() #4 /home/public_html/app/code/core/Mage/Core/Model/Email/Template/[login to view URL](74): Mage_Core_Block_Abstract->toHtml() #5 /home/public_html/lib/Varien/Filter/[login to view URL](128): Mage_Core_Model_Email_Template_Filter->blockDirective(Array) #6 /home/public_html/app/code/core/Mage/Cms/Block/[login to view URL](80): Varien_Filter_Template->filter(Array, Array) #7 /home/public_html/app/code/core/Mage/Core/Block/[login to view URL](643): Mage_Cms_Block_Page->_toHtml(' basically, as one of the links above posted "but when I go to my website, it comes with a long error message that in the top says that the category is invalid. The only way I can make the error disappear, is to change the id="25" to a number of category that doesn’t exist. here's the line of code i'm using in "Home page" {{block type="catalog/product_list" category_id="25" template="catalog/product/list.phtml"}} I need an explanation that will lead to the correction of this error, that is what I am paying for, I'm new here but I presume that people will bid and I will select the best offer and pay them to assist/provide consulting that will lead to correcting this. I need this done asap so bid happy, thanks!