MarketPress Cart Error

Hello,

When adding an item and going to shopping cart I get multiple errors and then am unable to proceed to checkout.

I disabled the plugin for a while and re-ativated it recently, went through all the settings to make sure everything was entered. What to do next?

Errors are

Warning: Illegal string offset 'echo' in /home/hitequip/public_html/cutlerypolisher.com.au/wp-content/plugins/marketpress/includes/public/class-mp-short-codes.php on line 222

Warning: Cannot assign an empty string to a string offset in /home/hitequip/public_html/cutlerypolisher.com.au/wp-content/plugins/marketpress/includes/public/class-mp-short-codes.php on line 222

Warning: array_replace_recursive(): Argument #2 is not an array in /home/hitequip/public_html/cutlerypolisher.com.au/wp-content/plugins/marketpress/includes/common/class-mp-cart.php on line 781

Warning: extract() expects parameter 1 to be array, null given in /home/hitequip/public_html/cutlerypolisher.com.au/wp-content/plugins/marketpress/includes/common/class-mp-cart.php on line 786

You can add a product here

https://cutlerypolisher.com.au/store/