Following folders have to be writable by the web server, that is is chmod-ed to 0777 recursive:
/apps/common/config
/apps/common/runtime
/backend/assets/cache
/frontend/assets/cache
/frontend/assets/files
/apps/extensions
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Following folders have to be writable by the web server, that is is chmod-ed to 0777 recursive:
/apps/common/config
/apps/common/runtime
/backend/assets/cache
/frontend/assets/cache
/frontend/assets/files
/apps/extensions