Error after logging in to front office: "no products"

[Soliloquy]

Every time I think I'm close to launching my PrestaShop, I come across a new problem. This time it started when I was testing out some things in the front end. I had some trouble logging in, so I reset and changed my password, added a few things to the cart, then logged out and tried to login again to see if it was still a problem. This time instead of a login error message, I got a white page saying:

 

 

Shopping Cart 0 Product Products 0

No products

Free shipping! Shipping

 

I turned on error logging and got some more information:

 

Notice: Undefined index: blockcart_cart_flag in /home/***/public_html/test/tools/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 379

Notice: Trying to get property of non-object in /home/***/public_html/test/tools/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 379

 

There was also a HUGE array of values, which I don't think I should paste in here, except for the 1st part which may have a clue:

Array(    [0] => Array        (            [file] => /home/***/public_html/test/classes/Cart.php            [line] => 1453            [function] => displayError            [class] => ToolsCore            [type] => ::            [args] => Array                (                )        )

 

(I'm not sure, but this problem might be related to another problem I've been having, which I thought was a problem with the theme until I ran into this. The theme I'm using has an "Add to Cart" that appears when you hover over the product image in the category listing, and it recently started giving me an error when pressed:

 

Impossible to add the product to the cart.
textStatus: 'parsererror'
errorThrown: 'SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data'
responseText:
Update and Add{"products":[{"id":189,"link":"http:\/\/www.blanketmybaby.com\/test\/animal-lovies\/189-angel-dear-new-panda-security-blankie.html","quantity":1,"image":"https:\/\/http://www.blanketmybaby.com\/test\/416-home_default\/angel-dear-new-panda-security-blankie.jpg","image_cart":"https:\/\/http://www.blanketmybaby.com\/test\/416-cart_default\/angel-dear-new-panda-security-blankie.jpg","priceByLine":"$13.00","name":"Angel Dear New Panda Security Blankie","price":"$13.00","price_float":13,"idCombination":0,"idAddressDelivery":5,"is_gift":false,"hasAttributes":false,"hasCustomizedDatas":false,"customizedDatas":[]},{"id":54,"link":"http:\/\/www.blanketmybaby.com\/test\/animal-lovies\/54-angel-dear-beige-bunny-blankie.html","quantity":3,"image":"https:\/\/http://www.blanketmybaby.com\/test\/112-home_default\/angel-dear-beige-bunny-blankie.jpg","image_cart":"https:\/\/http://www.blanketmybaby.com\/test\/112-cart_default\/angel-dear-beige-bunny-blankie.jpg","priceByLine":"$39.00","name":"Angel Dear Beige Bunny Blankie","price":"$39.00","price_float":39,"idCombination":0,"idAddressDelivery":5,"is_gift":false,"hasAttributes":false,"hasCustomizedDatas":false,"customizedDatas":[]}],"discounts":[],"shippingCost":"$7.00","shippingCostFloat":7,"wrappingCost":"$0.00","nbTotalProducts":4,"total":"$59.00","productTotal":"$52.00","freeShipping":"$45.92","freeShippingFloat":45.92,"hasError":false,"crossSelling":""}

 

I would appreciate any advice on how to get this straightened out. I promised my mom her new store months ago! :-(

[JeredBolton]

Impossible to add the product to the cart.
textStatus: 'parsererror'
errorThrown: 'SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data'
responseText:
Update and Add{"products":[{"id":189,"link":"

 

Where is the text "Update and Add" coming from?