Try once again using the Utility to remove it. Also this time, when you use the Classic Shell Utility to remove it, check the options to also remove all user settings.
Then reinstall the latest version. It should not crash.
If the taskbar disappears and appears again (as you describe screen "refreshing"), it means Explorer might be crashing for some reason when Classic Shell is installed. If removing it using the utility including all its settings does not work to fix it, capture a crash dump after installing Classic Shell using these instructions:
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