Thank you, @fredo6, for your response. I reinstalled SketchUp and all the plugins, and that resolved the issue. The plugins are working perfectly now.

@fredo6
After updating libfredo6 to the latest version (v14.5f), all of my Fredo plugins have stopped working. I have ensured that all the plugins are up to date. While the plugins are visible on the screen, nothing happens when I click on them.