SMF 2.0 RC3 : error packages

[blackpink]

Hi
I am french excuse me for my english.
Version : SMF 2.0 RC3 
I can not download or install new packages I have this error:
An error occurred!
You can not download or install new packages because the / packages is one of the files or is blocked in writing!
If you could help me and tell me how to fix this problem I thank you.
blackpink

[sander76]

You should search the forum for setting permissions on your files and folders. The error message says it all.

[vivid]

give folders permissions 777 or 775