can not save changes

[inception]

sorry for my bad english. I added two downloads. everything fine.
Then i create a categorie and it appears a message like "can not duplicated". But the categorie was added. Since i did that, i can not add preview pictures to a download. When i click on save, it shows "saved" but the picture is not added.
I can also not save changes in configuration. When i click on save, it appears the homepage from jdownloads. If i go back in configuration, nothing was saved. I put the debug feature on and when i open now a download in the backend it shows the following:
0 Cannot fput file for log

Call stack   
#      Function      Location   
1      JApplicationCms->execute()      /srv/www/htdocs/.../administrator/index.php:47   
2      JApplicationAdministrator->doExecute()      /srv/www/htdocs/.../libraries/cms/application/cms.php:252   
3      JApplicationAdministrator->dispatch()      /srv/www/htdocs/.../libraries/cms/application/administrator.php:152   
4      JComponentHelper::renderComponent()      /srv/www/htdocs/.../libraries/cms/application/administrator.php:98   
5      JComponentHelper::executeComponent()      /srv/www/htdocs/.../libraries/cms/component/helper.php:372   
6      require_once()      /srv/www/htdocs/.../libraries/cms/component/helper.php:392   
7      JControllerLegacy->execute()      /srv/www/htdocs/.../administrator/components/com_jdownloads/jdownloads.php:39   
8      JControllerForm->edit()      /srv/www/htdocs/.../libraries/legacy/controller/legacy.php:728   
9      JControllerLegacy->holdEditId()      /srv/www/htdocs/.../libraries/legacy/controller/form.php:421   
10      JLog::add()      /srv/www/htdocs/.../libraries/legacy/controller/legacy.php:925   
11      JLog->addLogEntry()      /srv/www/htdocs/.../libraries/joomla/log/log.php:151   
12      JLogLoggerFormattedtext->addEntry()      /srv/www/htdocs/.../libraries/joomla/log/log.php:280   
13      JLogLoggerFormattedtext->initFile()      /srv/www/htdocs/.../libraries/joomla/log/logger/formattedtext.php:120
Can you help me?

[ColinM]

Hi
I cannot actually tell what has gone wrong here but if you send me super user logon details by PM I will look further into the matter.  Incidentally was this a new install? Or have you updated from a previous jD 3.2 version? Or have yoiu recently migrated from a previous jd Version (jd2.5 jD1.9 for example)

Colin

[inception]

Thank you for your answer.

We have found the error an hour ago.
I had no more disc space on the server. now we have increased the space and it works fine again