Rather than check your syntax can I give you one that I know does work:
<h2><a name="Debriefing:End1"><br>Complete Success!</a></h2>
<p><br>
You have freed the island of soldiers.<br><br>
Your family and the rest of the population must now prepare for the coming nuclear winter. An important decision must be made immediately about the fate of any surviving soldiers. Does the island have the resources to support them?<br><br>
Do you wish to?
</p>
<br>
<hr>
<h2><a name="Debriefing:End2"><br>Partial Success</a></h2>
<p><br>
You have freed the island of soldiers, but unfortunately you failed to rescue all of the civilians.<br><br>
Your family and the rest of the population must now prepare for the coming nuclear winter. An important decision must be made immediately about the fate of any surviving soldiers. Does the island have the resources to support them?<br><br>
Do you wish to?
</p>
<br>
<hr>
<h2><a name="Debriefing:End3"><br>Partial Success</a></h2>
<p><br>
You have succeeded in killing all the soldiers and rescuing the civilian groups, but unfortunately you killed one of Stamenov's hostages.<br>
<br>
Your family and the rest of the population must now prepare for the coming nuclear winter. An important decision must be made immediately about the fate of any surviving soldiers. Does the island have the resources to support them?<br><br>
Do you wish to?
</p>
<br>
<hr>
<h2><a name="Debriefing:End4"><br>Partial Success</a></h2>
<p><br>
You have succeeded in killing all the soldiers, but unfortunately you failed to rescue all the civilians and you killed one of Stamenov's hostages.<br>
<br>
Your family and the rest of the population must now prepare for the coming nuclear winter. An important decision must be made immediately about the fate of any surviving soldiers. Does the island have the resources to support them?<br><br>
Do you wish to?
</p>
<br>
<hr>
<h2><a name="Debriefing:End6"><br>A failure</a></h2>
<p><br>
You failed to find your uncle Nikolai. <br>
<br>
Your family now have no hope of surviving the coming winter.
</p>
<br>
<hr>
I presume you remembered to end the mission with the appropriate trigger type (End1, end2 etc.