>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #2538818. --> Reported by: [jhedstrom](https://www.drupal.org/user/208732) >>> <p>If there are custom taxonomy formatters, the current upgrade path fails with:</p> <pre>Fatal error: Unsupported operand types in /Users/jhedstrom/work/clients/mskcc/mskcc_deploy/core/lib/Drupal/Core/Field/FormatterPluginManager.php on line 159</pre><p>since conversions are hardcoded:</p> <div class="codeblock"> <pre><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #FF8000">// Map taxonomy term reference formatters to entity reference ones.<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #007700">switch (</span><span style="color: #0000BB">$component</span><span style="color: #007700">[</span><span style="color: #DD0000">'type'</span><span style="color: #007700">]) {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case </span><span style="color: #DD0000">'taxonomy_term_reference_plain'</span><span style="color: #007700">:<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$type </span><span style="color: #007700">= </span><span style="color: #DD0000">'entity_reference_label'</span><span style="color: #007700">;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$settings </span><span style="color: #007700">= array(<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #DD0000">'link' </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">FALSE</span><span style="color: #007700">,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; );<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; break;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case </span><span style="color: #DD0000">'taxonomy_term_reference_link'</span><span style="color: #007700">:<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$type </span><span style="color: #007700">= </span><span style="color: #DD0000">'entity_reference_label'</span><span style="color: #007700">;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$settings </span><span style="color: #007700">= array(<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #DD0000">'link' </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">TRUE</span><span style="color: #007700">,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; );<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; break;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case </span><span style="color: #DD0000">'taxonomy_term_reference_rss_category'</span><span style="color: #007700">:<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$type </span><span style="color: #007700">= </span><span style="color: #DD0000">'entity_reference_rss_category'</span><span style="color: #007700">;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color: #0000BB">$settings </span><span style="color: #007700">= array();<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; break;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br></span><span style="color: #0000BB">?&gt;</span></span></pre></div> <p>if we can figure out an elegant way to support custom ones, that would be great, otherwise, noting this limitation (which can be worked around by custom patches).</p>