This issue has been fixed with version 1.3.4. The reason for this message is, that your ASA 2 cache is activated but the directory on the filesystem which ASA 2 wants to use for the cache data is not writable. By default, ASA 2 uses a WordPress internal function to determine a local directory with write access and tries to create a subdirectory called “asa2”. If that is not possible, you will receive this message. Please try to create the directory by yourself and set write permissions to it or set a custom directory with cache option File.