I recently upgraded a drupal 6 site into drupal 7 site almost successfully,
i am facing just a single issue, whenever i try to put site in maintenance mode it shows message on a white screen that Service Unavailable!

Here i want to load my drupal theme maintenance page layout rather than this white screen, please advise!

Comments

Strange. You may have a syntax error in a maintenance page theme template, or something of that kind. You should check server logs and Drupal recent log messages immediately after seeing the problem as there may be a clue there to what is causing the problem.

i checked again by enabling default theme Garland, still see the same message on white screen on maintenance mode, OK i will try to find something in logs!

Thank you

it shows these messages..

Warning: include(D:\wwwroot\xxxxx/sites/all/themes/xx_xxxx/templates/maintenance-page.tpl.php) [function.include]: failed to open stream: No such file or directory in theme_render_template() (line 1505 of D:\wwwroot\xxxxx\includes\theme.inc).

and

Warning: include() [function.include]: Failed opening 'D:\wwwroot\xxxxx/sites/all/themes/xx_xxxx/templates/maintenance-page.tpl.php' for inclusion (include_path='.;C:\php\pear') in theme_render_template() (line 1505 of D:\wwwroot\xxxxx\includes\theme.inc).

So do these messages help us to find solution? Please advise!
Thank you.

There should be a maintenance pate template in modules/system so it should not matter that it is missing from the theme (though you could always copy it from modules/system there if all else fails).

It looks as though there was a maintenance-page.tpl.php in the templates folder and it has been removed. Clearing caches should fix it.