I ran across another problem tonight with my Magneto installation.  For no good apparent reason my Add to Cart and Image Zoom suddenly stopped working.  I used the Firefox Error Console and this was my full error message:

Error: uncaught exception: [Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE)"  nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)"  location: "JS frame :: http://www.yoursite.com/magento/js/index.php?c=auto&f=,prototype/prototype.js,prototype/validation.js,scriptaculous/builder.js,scriptaculous/effects.js,scriptaculous/dragdrop.js,scriptaculous/controls.js,scriptaculous/slider.js,varien/js.js,varien/form.js,varien/menu.js,mage/translate.js,mage/cookies.js,varien/product.js,calendar/calendar.js,calendar/calendar-setup.js :: anonymous :: line 1528"  data: no]

After a lot of searching….well, I found nothing.  All the answers on the Magneto forum were no use to me at all.  After about 30 minutes of searching though, I did find an answer that works (at least for now).  I had to re-install the Lib_Js_Prototype using the Magnento Connect Manager.

Here is how you do that from the Magneto admin backend:

1) System – Magento Connect – Magento Connect Manager

2) You will be prompted for your admin user name and password

3) Select Lib_Js_Prototype and then choose from the drop down action menu Re-Install.

4) Click on Commit Changes

If everything goes ok, you should see something like this:

This seemed to solve the problem for me….at least for now.  Hopefully this works for you or at least helps you out somehow.

This morning I probably spent 15 minutes trying to figure out how to add an additional admin user to Magento. And although it turned out to be really easy, it took some digging to find the answer on the net. I finally found the answer on the forum board:

1. In your magento admin backend, go to Admin> System> Permissions> Users.
2. Click “Add new user”
3. Enter the user’s information.
4. Be sure to click on the “user roles” tab on the left menu to assign the account to a role. (You can create more limited-capability roles using ADMIN> System> Permissions> Roles so that users can’t reset anything too deadly if you want.)
5. Save user.

Hopefully this post helps to save someone else wasting 15 minutes looking for the answer on the magento forums.