I fixed this issue for me with a little bit logic – Ruco maybe you can use this snippet in the next Version – it just adds no a-Tag if there is no input for the link given:

https://pastebin.com/3SHAEH2b

 
<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”>Works with</p>

<ul style=”margin-left: .375in; direction: ltr; unicode-bidi: embed; margin-top: 0in; margin-bottom: 0in;” type=”disc”>
<li lang=”en-US” style=”margin-top: 0; margin-bottom: 0; vertical-align: middle;”><span style=”font-family: Calibri; font-size: 11.0pt;”>services_small.php</span>
<li lang=”en-US” style=”margin-top: 0; margin-bottom: 0; vertical-align: middle;”><span style=”font-family: Calibri; font-size: 11.0pt;”>services_medium.php</span>
<li lang=”en-US” style=”margin-top: 0; margin-bottom: 0; vertical-align: middle;”><span style=”font-family: Calibri; font-size: 11.0pt;”>services_large.php</span>

<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”></p>
<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”><span style=”font-weight: bold;”>Original:  </span></p>

<p lang=”en-US” style=”margin: 0in; font-family: Consolas; font-size: 11.0pt;”>$output .= ‘<h4>‘.esc_html($title).’</h4>’;</p>

<p lang=”en-US” style=”margin: 0in; font-family: Consolas; font-size: 11.0pt;”></p>
<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”><span style=”font-weight: bold;”>My Version:</span></p>

<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”>$output .= ‘<h4>’;</p>
<p lang=”en-US” style=”margin: 0in; font-family: Calibri; font-size: 11.0pt;”>$output .= empty($data[‘link’]) ? esc_html($title) : ‘‘.esc_html($title).’‘;
$output .= ‘</h4>’;</p>

Hello,

@sven, Thank you for the suggestion!

Best regards!