Successfully installed on laptop and tested. Repeated installation on project server. Edited email, server fields, etc. Ran admin/check.php, email test successful. Logged in as administrator and received error 401, text below:
Database query failed. Error received from database was 0001064: You have an error in your SQL syntax near 'on cft.id = cfpt.field_id
JOIN mantis_project_table as pt on' at line 3 for the query: SELECT distinct cft.id as id, cft.name as name
FROM mantis_custom_field_table as cft
JOIN mantis_custom_field_project_table as cfpt on cft.id = cfpt.field_id
JOIN mantis_project_table as pt on cfpt.project_id = pt.id
LEFT JOIN mantis_project_user_list_table as pult
on cfpt.project_id = pult.project_id and pult.user_id = 1
JOIN mantis_user_table as ut on ut.id = 1
WHERE pt.view_state = 10 OR
( pt.view_state = 50 and pult.user_id = 1 ) OR
( pult.user_id is null and ut.access_level >= 90 )
ORDER BY name ASC

Although issue was reported closed, it has happened to me.
All updates say they have been completed.