Hello I have downloaded https://marketplace.abantecart.com/avatax_integration?keyword=ava&category_id=0 and it shows it was developed by AbanteCart
I have downloaded it but I am not able to install it when I copy paste the folder in extension folder and go to my admin -> extension I don't see it there. I tried to install it by uploading .tar.gz file and then when I try to install it - it throws this error
2019-12-04 4:17:58 - warning: AbanteCart core v.1.2.11 unlink(C:/xampp/htdocs/folder/admin/system/backup/avatax_integration_2019-12-04-04-17-34.tar): Permission denied in <b>C:\xampp\htdocs\folder\core\helper\utils.php</b> on line <b>768</b>
2019-12-04 4:17:59 - App Error: AbanteCart core v.1.2.11 in C:\xampp\htdocs\folder\core\lib\package_manager.php on line 641

I see two files being copied in admin\system\backup folder one is .tar and another one is .tar.gz  no other error in error log just this two

Any solution ??

Have you tried this extension default_cod ?

Hi I ran into a strange problem. My site was up and running until yesterday and this morning all the product images are gone it throws 404 resource not found. When I go to Cpanel I can see that they are there but whem I hit the url
https://website.com/image/thumbnails/18/91/cars_jpeg-100636-250x250.jpeg  instead of showing me image it goes to my site and displays " THE PAGE YOU REQUESTED CANNOT BE FOUND!"

Strange this is permission to folder image is 755 thumbnails is 755 18 is 755 folder 91 is also 755 and image itself is 777
Now I am able to see logo as it comes from resource folder and permission over there is also same

No error in error log.

Can someone guide me my site is down no product images are being displayed not even on product page.

my store url are same I have not changed it and nothing was changed on serve as /resource folder is displaying images 

\storefront\controller\pages\checkout\cart.php

Yes it is related to permission
try to open one of this image in your browser
https://shop.crazygardener.in/image/thumbnails/18/7b/Manufact_lgO_png-100286-57x57.png

Hi,
I think there is some issue with session or cookie. I was able to reproduce this with v 1.2.11 , 1.2.13, 1.2.15
when user is logged in and made a purchase but then he/she forgets to log out and our site is open in one of the tab. When they open it next day they still see themselves as logged in 'Welcome Back UserName' but when they actually add product to their cart it asks them to sign in again.
I believe the cookie expires but can this be done by ajax so that its not confusing. If it shows them message on top saying 'Welcome Back UserName' and then asking them to sign in. As they can hover on it and see all the options that are there for signed in user like 'log off', 'account dashboard' etc.

You can add whatsapp icon to product page that's simple but how do you think you will get customer's phone number because from what I read is you will need customers phone number to initiate that chat.

To insert icon on product page you can add your code inside this div or above it based on your requirement
https://github.com/abantecart/abantecart-src/blob/master/public_html/storefront/view/default/template/pages/product/product.tpl#L127

Options I can think of is either customer has to be logged in with correct phone number that has been connected to his/her whatsapp or second option is you can create a small pop-up form which appears when they click on that icon and you ask for their phone number and when they enter their phone number you can send a whatsapp message to yourself from that number along with the product page link.

Check this extension https://marketplace.abantecart.com/promotions/si_whatsapp

have you made any changes in your .htaccess file?