If you are receiving an error like this and have deleted the cache file and get the same result then the issue may be a corruption of your configuration folder. Did you try the steps from any of the previous posts for this? If not here is a link, you will want to try the section about renaming the configuration folder. This will cause the extensions to be uninstalled, you will need to re-install them to make use of the tools.
If after doing this you still have the same problem please let us know and I can get a ticket opened for you so that this issue can be looked into further.