Error with shoppingcart.headerquantity

I installed a theme and uninstalled it.

Now, default theme shows the following entries:

shoppingcart.headerquantity
wishlist.headerquantity

How can I fix this?

Fixed!

In Configuration > Language, I added the following entries for each of the resource values:

({0})

Can you be more specific, at the end of which lines did you add this?
And what is correct like this ({0}) or like this ('{0}')? It's just that some records have this ('{0}').

for the given resource string this is the value you can add

 <LocaleResource Name="ShoppingCart.HeaderQuantity">
    <Value>({0})</Value>
  </LocaleResource>

<LocaleResource Name="Wishlist.HeaderQuantity">
    <Value>({0})</Value>
  </LocaleResource>

you can directly add the value ({0})
you can get more ideas using the screenshot

https://yourstore.com/Admin/Language/Edit/1
can edit from here also

Thanks a lot. Made as in the screenshot. I didn't have the shoppingcart.headerquantity line at all. I added it and entered the desired value. Now everything is as it should be. Thanks again.