Vendor service unavailable suddenly

This is a first.
I had a new vendor creator an account, everything went smooth, he had no problems. Several hours later he logs into the site and now only sees Service Unavailable all of a sudden.
I can replicate this when I log in under his account.
It’s the only vendor that seems affected by this but I haven’t a clue what suddenly caused this or how to correct it.

Upon checking the source of the page;
SmartyException

Message
Unable to load template ‘tygh:common/icon_deprecated.tpl’

Error at
app/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php, line: 196

Backtrace
File:app/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php
Line:238
Function:render

I’m a bit concerned. I created another vendor account and experienced the same issue. Ever since a developer made some “changes,” to fix issues with their addon, new vendors can no longer sign up properly—they’re only able to access the backend.

I really like this platform, but after all these years of using it, it feels like every time one issue gets “fixed,” several new ones inevitably pop up. It’s just frustrating.

At first try to create the following file

/design/backend/templates/common/icon_deprecated.tpl

{if $class}{strip}<span 
        class="cs-icon {$class}" {""}
        {if $id}
            id="{$id}" {""}
        {/if}
        {if $title}
            title="{$title}" {""}
        {/if}
        {if fn_is_rtl_language()}
            dir="rtl" {""}
        {/if}
        {if $data}
            {foreach $data as $data_name => $data_value}
                {if $data_value}
                    {$data_name}="{$data_value}" {""}
                {/if}
            {/foreach}
        {/if}
    >{if $icon_text}{$icon_text nofilter}{/if}</span>{/strip}{/if}

Then clear cache and check

I may try that. However, I would like.to understand why or what would have caused this all of a sudden?

you look at error.log file to see if there is any error

Try replacing this code:

     {if $image_data.image_path}
         <img {$image_attributes|render_tag_attrs nofilter} />
     {else}
        <div class="no-image {$no_image_css_class}" style="width: {$image_width|default:$image_height}px; height: {$image_height|default:$image_width}px;">{include_ext file="common/icon_deprecated.tpl" class="glyph-image" title=__("no_image")}</div>
     {/if}
     {if $show_detailed_link && ($image || $href)}</a>{/if}

with this one:

     {if $image_data.image_path}
         <img {$image_attributes|render_tag_attrs nofilter} />
     {else}
        <div class="no-image {$no_image_css_class}" style="width: {$image_width|default:$image_height}px; height: {$image_height|default:$image_width}px;">{include_ext file="backend:common/icon_deprecated.tpl" class="glyph-image" title=__("no_image")}</div>
     {/if}
     {if $show_detailed_link && ($image || $href)}</a>{/if}

in the design/backend/templates/common/image.tpl file.

We have an internal bug report for this error. Most likely your case is the same as the one we already have.

Could you possibly tell me what line I should find this on?

This should be the 29th line.