I'm getting this error too - also with downloading stuff from the marketplace and themes etc.

Thought it was because I have recently moved to a new hosting server and some of the owner/group permissions on folders and files got reset to 99 (nobody).

See here:http://www.concrete5.org/community/forums/installation/problem-with...

Correcting this problem solved my inability to upload images via the File Manager - but I'm still getting the Zip unpacking problem!

Do you have zip installed? If you're not sure, goto dashboard -> sitewide settings -> debug and post the contents of the Environment box...

Jon

Also, double check your permissions. For packages and updates you ned to do this from a terminal (I'm assuming your webserver is running as 'apache')
# chgrp -R apache updates packages
# chmod -R g+rX updates packages

Jon

This is the contents of the Environment box:

# concrete5 Version
5.4.0.5

# concrete5 Packages
Dreamy (1.0), earthling two theme (1.0), Featuring Theme (1.0), Pluralism (1.1), Soul Mate (1.01).

# concrete5 Overrides
None

# Server Software
Apache

# Server API
cgi

# PHP Version
5.2.14

# PHP Extensions
bcmath, calendar, cgi, ctype, curl, date, dom, filter, ftp, gd, hash, iconv, imap, ionCube Loader, json, libxml, mbstring, mcrypt, mhash, mime_magic, mysql, mysqli, openssl, pcre, PDO, pdo_mysql, pdo_sqlite, posix, Reflection, session, SimpleXML, sockets, SPL, SQLite, standard, suhosin, tokenizer, xml, xmlreader, xmlwriter, Zend Optimizer, zlib.

# PHP Settings


But I think you're right - I don't see Zip mentioned anywhere there!

just realised that it's not showing me the PHP Settings in the above.

Maybe because we are running suPHP on this new server?

Ok Update on this:
Just received this from our server guy:

'Unzip command line is installed on the server, however the module compiled into apache/php cannot talk to it yet - I need to rebuild apache/php config to do this - the rebuid takes about an hour.'

This may sort my problem anyway!

# concrete5 Version
5.4.0.5

# concrete5 Packages
AddThis Bar (1.0), Black Accents (1.2), blogga (1.0.), Breadcrumbs (1.0), Content Around Image (1.23), Cu3er Slideshow (1.1.4), Dojo Content Highlight (1.2), Dynamic Iframe (1.3), Easy News (1.1), Example FAQ (1.0), Expander (1.0), Galleria image gallery (2.0), Google Tagcloud (1.5), Login (1.0), Mint Chocolate Chip (1.0), Orange Sunset (1.2), Page Ear (1.2.2), Page List Teasers (1.01), ShareThis (1.0), Soft_News (1.0), Sortable Fancybox Gallery (1.12), Stylized (1.0), Tag Cloud (1.0), Thumbview Template (1.1.1), tnSpacer (1.2), Xclydes Utilities (1.0.6), Yosemite (1.0), Zoom Image (1.0.1).

# concrete5 Overrides
None

# Server Software
Apache/2.2.9 (Debian) PHP/5.2.6-1+lenny8 with Suhosin-Patch mod_ssl/2.2.9 OpenSSL/0.9.8g

# Server API
apache2handler

# PHP Version
5.2.6-1+lenny8

# PHP Extensions
apache2handler, bcmath, bz2, calendar, ctype, curl, date, dba, dom, exif, filter, ftp, gd, gettext, hash, iconv, imap, json, ldap, libxml, mbstring, mcrypt, mime_magic, mysql, mysqli, openssl, pcre, PDO, pdo_mysql, posix, Reflection, scriptat, session, shmop, SimpleXML, soap, sockets, SPL, standard, sysvmsg, sysvsem, sysvshm, tokenizer, wddx, xml, xmlreader, xmlwriter, zip, zlib.

# PHP Settings
log_errors_max_len - 1024
max_execution_time - 30
max_file_uploads - 50
max_input_nesting_level - 64
max_input_time - 600
memory_limit - 128M
post_max_size - 20M
safe_mode - Off
safe_mode_exec_dir - <i>no value</i>
safe_mode_gid - Off
safe_mode_include_dir - <i>no value</i>
sql.safe_mode - Off
suhosin.log.phpscript.is_safe - Off
upload_max_filesize - 20M
mysql.max_links - Unlimited
mysql.max_persistent - Unlimited
mysqli.max_links - Unlimited
pcre.backtrack_limit - 100000
pcre.recursion_limit - 100000
session.cache_limiter - nocache
session.gc_maxlifetime - 7200
soap.wsdl_cache_limit - 5
safe_mode_allowed_env_vars - PHP_
safe_mode_protected_env_vars - LD_LIBRARY_PATH

hoxton, the info looks fine, i think its just a permissions issue,

Thanks mate merry xmas