Software error: Template process failed: file error - /usr/share/koha/opac/htdocs/opac-tmpl/prog/en/modules/errors/404.tt: not found at /usr/share/koha/lib/C4/Templates.pm line 132. For help, please send mail to the webmaster ([no address given]), giving this error message and the time and date of the error. Please help me, how to fix this.
This sounds like a support request rather than a bug report. Please consult your options for getting Koha support: http://koha-community.org/support/ ...particularly the Koha mailing list. Keep in mind that any requests for help should include the version of Koha you are using and detailed description of what led to the error.