WordPress Speed Up Service | WordPress Website Maintenance Packages The plugin does not have a valid header., by jfletty i just installed w3 total cache and just activated in and came up with multiple error messages saying [plugin] has been deactivated due to an error: The plugin does not have a valid header. This seems to not just deactivated them but deleted them. 8 puygins that are very important to my website running and now its all gone. is there a way to recover these or bring them back/ activate them? The plugin does not have a valid header.