This solution is for you If you see the following error using Flexy Templates:
HTML_Template_Flexy fatal error: HTML_Template_Flexy::failed to write to /dirname/etc...
go into your ftp client and find the lib directory for your Flex engine. The file you want is called class.page.php. You have to find the compileDir and templateDir variables and set them all to the correct path. What worked for me was using the entire path instead of the path from the directory the file was in, so I used something like this for the compileDir:
and something like this for the templateDir:
what you need to use will depend on your directory structure, so figure it out by finding the two respective directories and figuring out their complete paths.