Here is the returned custom xml comment that I can reproduce my VS Enterprise 2017 with. Note the formatting was changed when it got put back in the code with WYSIWYG but with cursor in the comment and click WYSIWYG and then click add "Exception" it crash, but now after a complete restart of my system it is working without crashing VS. I believe this is a MS issue not yours since I am a Windows Insider running build 16226rs_prerelease.170616-2021. I have seen that VS Enterprise 2016 will not completely install all component using the last two insider builds.
/// <summary>
/// Gets the difference from start end times.
/// </summary>
/// <param name="fullPath">
/// The full path.
/// </param>
/// <returns>
/// TimeSpan.
/// </returns>
/// <remarks>
/// <p>
/// <b>History:</b>
/// </p>
/// <div class="tableSection">
/// <table width="100%" frame="lhs" cellSpacing="2" cellPadding="5">
/// <tbody><tr>
/// <th>Developer\Date\Time</th>
/// <th>Developer Company</th>
/// <th>Developer Phone</th>
/// <th>Developer Email</th>
/// <th>Developer On</th>
/// <th>Description</th>
/// </tr>
/// <tr>
/// <td>
/// Developer: Danny C. McNaught
/// <p>Date: Thursday, March 30, 2017</p><p>Time: 4:26 PM</p></td>
/// <td>United States Postal Service</td>
/// <td>(919) 424-9259</td>
/// <td>
/// <a href="mailto:danny.mcnaught@dxc.com">mailto:danny.mcnaught@dxc.com</a>
/// <p>
/// <a href="mailto:danny.c.mcnaught@usps.gov">mailto:danny.c.mcnaught@usps.gov</a>
/// </p>
/// <p>
/// <a href="mailto:sfcsarge@outlook.com">mailto:sfcsarge@outlook.com</a>
/// </p>
/// </td>
/// <td>SURFACEPRO3</td>
/// <td>Created XML Comment</td>
/// </tr>
/// </tbody></table>
/// </div>
/// </remarks>