This text is not mine, it is from b.giraudier AT focal.NOSPAMfr 21-Jun-2005 11:34 http://manual.mantisbt.org/manual.customizing.mantis.custom.fields.php.
I have the same problem and don't find a reference to it in this issue tracking database.

A bug fix is described there:

tryweb@ichiayi.com
06-Jul-2005 12:29 #501

After traced manage_proj_edit_page.php & custom_field_api.php, I think the problem should be from the table, mantis_custom_field_project_table, no row.

In custom_field_api.php -> function custom_field_get_ids
the SQL statement need to join mantis_custom_field_project_table; however, there is no row in the table.

I hope the information is helpful for developers.

tryweb@ichiayi.com
06-Jul-2005 13:14 #502

Actually I just had solved the problem.

Just update custom_field_api.php (mantis/core/)

search the key word : "function custom_field_get_ids"

update 1:
if ( ALL_PROJECTS == $p_project_id ) <-- before update
if ( ALL_PROJECTS != $p_project_id ) <-- after update

Update 2:
$query = "SELECT $t_custom_field_table.id, $t_custom_field_table.name
FROM $t_custom_field_table, $t_custom_field_project_table
WHERE $t_custom_field_project_table.project_id = '$p_project_id' AND
$t_custom_field_table.id = $t_custom_field_project_table.field_id
ORDER BY name ASC"; <-- brfore update

$query = "SELECT $t_custom_field_table.id, $t_custom_field_table.name
FROM $t_custom_field_table
ORDER BY name ASC"; <-- after update

Jonathan Tsai.