Error when placing an order

After installing and configuring the plugin with the Paystack API key, etc. When I attempt to place an order (on both test and live mode) it shows the error on a bootstrap alert:
Sorry, this order is invalid and cannot be paid for.
Also the plugin is deactivated with the message:
The plugin woo-paystack/woo-paystack.php has been deactivated due to an error: The plugin does not have a valid header.

I have had to repeat the loop of installing, attempting to order and reinstalling again several times, please help!

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