after my forum searches to solve the problem, find a topic with the same problem as mine, which says that solved the problem in the following.
Ok I fixed the problem.
Yes it happened with all formats.
The problem lies in php.ini. It uses the c:\windows\temp folder as the temporary upload folder before it moves the files to oc-content/uploads.
In general the c:\windows\temp folder does not have IUSR_USER permissions to write. I added write permissions and woulla! Everything works fine.
Mark as RESOLVED and hopefully others will have use of this information as well.
Now to look for a good membership plugin
I have the same problem. Can anyone explain me how to do, you please tell me how you resolved the problem step by step?
Thanks