If the error occurs on a blank wordpress installation, then it suggests the issue comes from the server itself. If the issue affects all other Wordpress installation from Infinityfree, then why is it that you’re the only one who have reported the issue on this forum considering that majority of the Infinityfree users use Wordpress? 
I can see that you’ve used a plugin to import a specific page. I want to ask whether you’ve used that plugin on a blank wordpress installation or not. I hope you’re not busy bothering with wild guesses but I suspect that the issue is somehow connected on how you’ve imported and exported your Wordpress site. As far as I know, both Infinityfree and Wordpress does not recommend any plugin for importation and exportation. It has to be done manually.