I have been running Joomla 1.7 on my ubuntu 10.04 on localhost.It was running smoothly on my localhost machine without giving any problem. After I have completed all my task on localhost I thought to upload my local joomla to online.I used Filezilla , ftp program for transferring all my files to remote server. Successfully I saved my Joomla 1.7 on remote host.
In remote host or can say online, I see my site (frontend ) was running smoothly without any error. When I tried to access my backend Joomla gave me throwing error like above screen shot. I double check my configuration.php but everything seems to O.K.
I googled for above error ,most of the solution was telling me to give 777 to cache,tmp and log. But It was not working for me.
Then I changed path of tmp and log in configuration.php. As my online server is not in ubuntu , It was on Redhat Linux. After changing actual path of tmp and log , I get my backend also working.