Foswiki/Users/HtPasswdUser.pm did not return a true value

I've installed Foswiki 1.0.5 on a subdomain of my domain at DreamHost, but I am having problems with the password manager:

When I view a page, I get the error listed below.
To troubleshoot this, I tried to set the password manager to none in configure, and the pages then view just fine. So I think it's not a permission thing in bin or in data.
When I set it to HtPasswdUser I get the error listed. When I try ApacheHtpasswdUser instead, I get a different error but still no success.
I've checked that all paths in configure are correct, including the path to .htpasswd which is also set to 0644.
I've also googled, and searched here, for keywords in the error message, but I came up blank.
I've installed TWiki several times over the years and feel I am reasonably well versed. But this is my first Foswiki 1.0.5 install. One Foswiki 1.0.0 install I did earlier succeeded, but I can't determine any difference.

--> How can I resolve this error?

Software error:
Foswiki/Users/HtPasswdUser.pm did not return a true value at (eval 26) line 3.
 at (eval 26) line 3
 eval 'require Foswiki::Users::HtPasswdUser
;' called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users/TopicUserMapping.pm line 81
 Foswiki::Users::TopicUserMapping::new('Foswiki::Users::TopicUserMapping', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users.pm line 123
 Foswiki::Users::new('Foswiki::Users', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki.pm line 1352
 Foswiki::new('Foswiki', 'undef', 'Foswiki::Request=HASH(0x525c80)', 'HASH(0xb1d5a0)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 276
 Foswiki::UI::_execute('Foswiki::Request=HASH(0x525c80)', 'CODE(0xb34880)', 'view', 1) called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 258
 Foswiki::UI::handleRequest('Foswiki::Request=HASH(0x525c80)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Engine/CGI.pm line 26
 Foswiki::Engine::CGI::run('Foswiki::Engine::CGI=HASH(0x92e790)') called at view line 45
For help, please send mail to the webmaster (webmaster@lex.gebeconsult.com), giving this error message and the time and date of the error.
Software error:
[Fri Jun 19 22:05:10 2009] view: Foswiki/Users/HtPasswdUser.pm did not return a true value at (eval 26) line 3.
[Fri Jun 19 22:05:10 2009] view: at (eval 26) line 3
[Fri Jun 19 22:05:10 2009] view: eval 'require Foswiki::Users::HtPasswdUser
[Fri Jun 19 22:05:10 2009] view: ;' called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users/TopicUserMapping.pm line 81
[Fri Jun 19 22:05:10 2009] view: Foswiki::Users::TopicUserMapping::new('Foswiki::Users::TopicUserMapping', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users.pm line 123
[Fri Jun 19 22:05:10 2009] view: Foswiki::Users::new('Foswiki::Users', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki.pm line 1352
[Fri Jun 19 22:05:10 2009] view: Foswiki::new('Foswiki', 'undef', 'Foswiki::Request=HASH(0x525c80)', 'HASH(0xb1d5a0)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 276
[Fri Jun 19 22:05:10 2009] view: Foswiki::UI::_execute('Foswiki::Request=HASH(0x525c80)', 'CODE(0xb34880)', 'view', 1) called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 258
[Fri Jun 19 22:05:10 2009] view: Foswiki::UI::handleRequest('Foswiki::Request=HASH(0x525c80)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Engine/CGI.pm line 26
[Fri Jun 19 22:05:10 2009] view: Foswiki::Engine::CGI::run('Foswiki::Engine::CGI=HASH(0x92e790)') called at view line 45
 at /usr/share/perl/5.8/CGI/Carp.pm line 314
 CGI::Carp::realdie('[Fri Jun 19 22:05:10 2009] view: Foswiki/Users/HtPasswdUser.p...') called at /usr/share/perl/5.8/CGI/Carp.pm line 400
 CGI::Carp::die('') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users/TopicUserMapping.pm line 82
 Foswiki::Users::TopicUserMapping::new('Foswiki::Users::TopicUserMapping', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Users.pm line 123
 Foswiki::Users::new('Foswiki::Users', 'Foswiki=HASH(0xb34740)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki.pm line 1352
 Foswiki::new('Foswiki', 'undef', 'Foswiki::Request=HASH(0x525c80)', 'HASH(0xb1d5a0)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 276
 Foswiki::UI::_execute('Foswiki::Request=HASH(0x525c80)', 'CODE(0xb34880)', 'view', 1) called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/UI.pm line 258
 Foswiki::UI::handleRequest('Foswiki::Request=HASH(0x525c80)') called at /home/tomgb/lex.gebeconsult.com/lib/Foswiki/Engine/CGI.pm line 26
 Foswiki::Engine::CGI::run('Foswiki::Engine::CGI=HASH(0x92e790)') called at view line 45
For help, please send mail to the webmaster (webmaster@lex.gebeconsult.com), giving this error message and the time and date of the error.

Sounds rather like the perl module has got corrupted. All perl modules have to be terminated with a "true value" - in practice this means that the last (code) line of the file has to be:

1;

Check the Foswiki/Users/HtPasswdUser.pm and ensure it ends this way (the 1; will usually be followed by comments e.g.

1;
__DATA__
Everything after __DATA__ or __END__ is ignored

If the 1; is missing, then the perl module has been corrupted.

(Another check you can do is to 'cd' to the lib directory and type: perl -I . Foswiki/Users/HtPasswd.pm - if you get errors, same analysis)

-- CrawfordCurrie - 29 Jun 2009

Crawford, thank you! You were absolutely right, HtPasswdUser.pm had become corrupted. I would never have found out without your precise comment. FIXED!

When I investigated this error earlier, I also copied all Foswiki files to the webserver again, overwriting the ones there. I did not notice that HtPasswdUser.pm was somehow locked. I noticed it now while investigating your answer, that I was able to open and read the file, but it appeared empty. I could not save any changes. In the end I was able to delete it entirely and then copy over the original from my local system -- and everything immediately began working!

-- TorbenGB - 17 Jul 2009