Hi @wpshushu,
Thank you for contacting us and I hope you are doing well, We are unable to replicate the mentioned issue on our testing sites although you can troubleshoot this issue by switching to the WordPress default 2022 theme and deactivating other plugins one by one.
However, the Invalid header error can also be fixed by clicking the back button from the browser and reactivating the plugin.
Just to let you know, this issue appears on specific configurations.
Thanks
@arsalantariq Have you tested on WP 5.9.1?
@arsalantariq The problem appears to be if I click the Activate button right after plugin installation, I got the “invalid header error”. But if I go to plugins and activate it manually from the plugins list, it activated successfully.
Hi @wpshushu,
Yes, we have checked with WordPress Version 5.9.1 and we are unable to reproduce the mentioned issue.
Kindly update the plugin to its latest version 4.0.1 and then check.