Steps to reproduce the issue

Use the custom XML update server in Joomla Update
https://update.joomla.org/core/nightlies/next_patch_list.xml
try to update and see php error log

Expected result

no php error

Actual result

PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:48: parser error : Opening and ending tag mismatch: fieldset line 23 and field in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): </field> in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:49: parser error : expected '>' in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): </fieldset> in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:50: parser error : Opening and ending tag mismatch: config line 21 and fields in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): </fields> in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:51: parser error : Opening and ending tag mismatch: extension line 2 and config in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): </config> in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:52: parser error : Extra content at the end of the document in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): </extension> in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 1997
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:48: parser error : Opening and ending tag mismatch: fieldset line 23 and field in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): </field> in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:49: parser error : expected '>' in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): </fieldset> in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:50: parser error : Opening and ending tag mismatch: config line 21 and fields in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): </fields> in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:51: parser error : Opening and ending tag mismatch: extension line 2 and config in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): </config> in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): /plugins/fields/radio/radio.xml:52: parser error : Extra content at the end of the document in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): </extension> in /libraries/cms/installer/installer.php on line 2215
PHP Warning: simplexml_load_file(): ^ in /libraries/cms/installer/installer.php on line 2215

System information (as much as possible)

Joomla 3.7.2 --> 3.7.3dev

Additional comments