7
First of all,
when you get a blank page, turn on PHP-debug mode in the system admin -> preferences -> general settings page. Then, return to the page that produces the blank page, and note the errors that cause the page to break. That way you can detrmine the offending broken code, and we can give a specific answer. XOOPS is a complex system, without this information we're just guessing.
Secondly, the chmod issue. This is a command for linux and unix (web)servers to set the read/write/execute rights for each file and folder. To set multiple combinations quickly, this command works with 3 digit combinations. 444 is read only, 666 is read and write, 777 is full access rights. XOOPS requires the cache/, templates_c/ and uploads/ folders to be given full access rights (chmod 777).
Setting these rights depend on where you're running the webserver (if it's a localhost or on space provided by the hoster), the server's operating system (is it a windows server or a linux/unix server), and the FTP client (to give the chmod command itself). The most common setup would be you have uploaded the filesd to a webspace on a shared hosting provider, using a linux webserver. That means it depends on your FTP client. Most clients I have worked with have a 'properties' or 'commands' menu in the right-click contextual menu. Thus, rightclick on the uploads/ folder, select 'properties' or 'commands', and then select CHMOD. Check your FTP client's help menu for clear instructions on how to CHMOD a file or folder.
I hope this makes it more clear for you
Herko