Thanks for getting in touch. We’ve seen that fatal error before in very old versions of our TubePress plugin. We would recommend that you update to the latest version (5.1.8) here1; this2 series of documentation may be useful to have on hand. We’d also advise that you remove any old copies of the TubePress plugin from wp-content/plugins.
If you continue to have any issues, please let us know – we’re happy to assist!
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