Unable to install any plugin

[sdx]

So I'm new to Freenas and with a few frustrations I managed to get it up and running with the correct shares and user rights.

However, I'm not able to install any plugins :(
I've tried factory resetting without avail...

My setup is:
- CPU: Intel Pentium G3420
- Mobo: Gigabyte H87M-D3H
- RAM: 8GB DDR3 non-ECC (will be upgrading to 16GB in a few days)
- 3 x 3TB in RaidZ1 + 1 x 4TB in Stripe

Yesterday I tried installing the miniDLNA plugin for the 50th time.
Usually it starts installing and I can see the progress bar moving. After a little while that popup disappears and nothing happened. When I go to check on installed plugins, nothing is there.
However, yesterday I actually got the following message but I have no idea what this means:

Request Method: POST
Request URL:http://192.168.1.28/plugins/plugin/...67232389958ab24d67ca89acf215db20019ae27d7e2f/
Software Version:FreeNAS-9.2.1.2-RELEASE-x64 (002022c)
Exception Type:TypeError
Exception Value:
format requires a mapping
Exception Location:/usr/local/www/freenasUI/../freenasUI/plugins/plugin.py in download, line 122
Server time:Sun, 16 Mar 2014 05:27:55 -0700
Traceback

Request information

GET

No GET data
POST

VariableValue
__form_idu'form_str'
FILES

No FILES data
COOKIES

VariableValue
csrftoken'Xhkdjlnv46bPjsuCET1lhJGrPumEKTQS'
sessionid'nlm2qg9w2ly8jv7uqyejt8br050243uu'
fntreeSaveStateCookie'root%2Croot%2F35%2Croot%2F1%2F2%2Croot%2F1%2F6%2Croot%2F100%2Croot%2F90%2Croot%2F90%2F97%2Croot%2F1%2F5%2Croot%2F94%2F101%2Croot%2F52%2F59%2F60%2F61%2F66%2Croot%2F52%2F59%2Croot%2F52%2F59%2F60%2Croot%2F52%2F59%2F60%2F61%2Croot%2F153%2Croot%2F52%2F59%2F60%2F77%2Croot%2F36%2F38%2Croot%2F9'
META

VariableValue
wsgi.multiprocessFalse
HTTP_REFERER'http://192.168.1.28/'
REDIRECT_STATUS'200'
SERVER_SOFTWARE'nginx/1.4.4'
SCRIPT_NAMEu''
HTTP_X_CSRFTOKEN'Xhkdjlnv46bPjsuCET1lhJGrPumEKTQS'
REQUEST_METHOD'POST'
PATH_INFOu'/plugins/plugin/install/174ccb1f4e0f396fdf3a67232389958ab24d67ca89acf215db20019ae27d7e2f/'
HTTP_ORIGIN'http://192.168.1.28'
SERVER_PROTOCOL'HTTP/1.1'
QUERY_STRING''
CONTENT_LENGTH'18'
HTTP_USER_AGENT'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36'
HTTP_CONNECTION'keep-alive'
HTTP_COOKIE'sessionid=nlm2qg9w2ly8jv7uqyejt8br050243uu; csrftoken=Xhkdjlnv46bPjsuCET1lhJGrPumEKTQS; fntreeSaveStateCookie=root%2Croot%2F35%2Croot%2F1%2F2%2Croot%2F1%2F6%2Croot%2F100%2Croot%2F90%2Croot%2F90%2F97%2Croot%2F1%2F5%2Croot%2F94%2F101%2Croot%2F52%2F59%2F60%2F61%2F66%2Croot%2F52%2F59%2Croot%2F52%2F59%2F60%2Croot%2F52%2F59%2F60%2F61%2Croot%2F153%2Croot%2F52%2F59%2F60%2F77%2Croot%2F36%2F38%2Croot%2F9'
SERVER_NAME'localhost'
REMOTE_PORT'55329'
wsgi.url_scheme'http'
SERVER_PORT'80'
SERVER_ADDR'192.168.1.28'
DOCUMENT_ROOT'/usr/local/etc/nginx/html'
HTTP_CONTENT_LENGTH'18'
HTTP_X_REQUESTED_WITH'XMLHttpRequest'
DOCUMENT_URI'/plugins/plugin/install/174ccb1f4e0f396fdf3a67232389958ab24d67ca89acf215db20019ae27d7e2f/'
wsgi.input<flup.server.fcgi_base.InputStream object at 0x8157c06d0>
HTTP_HOST'192.168.1.28'
wsgi.multithreadTrue
HTTP_CONTENT_TYPE'application/x-www-form-urlencoded'
REQUEST_URI'/plugins/plugin/install/174ccb1f4e0f396fdf3a67232389958ab24d67ca89acf215db20019ae27d7e2f/'
HTTP_ACCEPT'*/*'
wsgi.version(1, 0)
GATEWAY_INTERFACE'CGI/1.1'
wsgi.run_onceFalse
wsgi.errors<flup.server.fcgi_base.TeeOutputStream object at 0x8157c0710>
REMOTE_ADDR'192.168.1.20'
HTTP_ACCEPT_LANGUAGE'nl-NL,nl;q=0.8,en-US;q=0.6,en;q=0.4,fr;q=0.2'
CONTENT_TYPE'application/x-www-form-urlencoded'
CSRF_COOKIEu'Xhkdjlnv46bPjsuCET1lhJGrPumEKTQS'
HTTP_ACCEPT_ENCODING'gzip,deflate,sdch'

I've searched the forums for a solution, but nothing helped.
Hopefully someone here can help me out...

 

[sdx]

Also this message keeps coming up in the logs:

../source3/lib/util_sock.c:1199(get_remote_hostname)
Mar 17 03:27:49 sdxnas smbd[50413]: matchname failed on 192.168.1.27

I tried adding the host names of all computers in my network in the field Host Name Database under Network > Global Config, but that doesn't seem to help much...

 

[dlavigne]

format requires a mapping

It's definitely a DNS problem. Is there a DNS server in the network? If so, make sure it's IP address is set in Network -> Global Configuration.