Dropdown List of Tags

[valarcher]

Hi - I’m having problems with my drop down list of tags at:
http://greensmoothie.com/posts (scroll down to sub-header “Archives by Tag”)

In the past, when I clicked on a tag, it went to, e.g.:
gs.com/tag/quinoa

Instead now it gives this result and a 404 error:
gs.com/?cat=20

If I enter it manually in browser (*/tag/quinoa") the URL displays correctly.

Does anyone know why wordpress is now displaying it as “?cat=20” and NOT as “tag/quinoa”

I’m using this:

<form action="<?php bloginfo('url'); ?>/" method="get">
<?php
$select = wp_dropdown_categories('taxonomy=post_tag&show_option_none=Select Tag&show_count=1&orderby=name&echo=0');
$select = preg_replace("#<select([^>]*)>#", "<select$1 onchange='return this.form.submit()'>", $select);
echo $select;
?>
<noscript><input type="submit" value="View" /></noscript>
</form>

which I got from:
http://technolect.org/create-dropdown-list-tags/

Do I need to set anything in the “tag base” option in Settings/Permalinks? I never used to set anything in permalinks. This linking to a cat # is recent aberration, I guess caused by a wordpress upgrade.

I tried disabling all plugins but that made no difference.

(2) In my dropdown list of Categories, how do I exclude the category “Test Posts”? I’m looking at this but can’t see a way:

https://codex.wordpress.org/Function_Reference/wp_dropdown_categories

thank you! - Val

[WebMachine]

Have you checked out the Codex on permalinks - https://codex.wordpress.org/Using_Permalinks ? There’s a pretty thorough discussion here including the use of tags in the URL here.

[valarcher]

Sorry I forgot to mention, it can’t be a permalinks problem because if I go to an actual post, e.g:

http://greensmoothie.com/recipes/buckwheat-porridge

scroll down to end, click quinoa tag, and it goes to the correct gs.com/tag/quinoa URL.

It must be a problem in the dropdown script. That script used to work correctly, but stopped with a wordpress upgrade.