Addition to previous post: I neglected to mention that I used this plugin with the same site a few weeks ago to migrate it onto the present server with no issue.
I’m getting this error as well. The backup file is ~293MB, and I bumped PHPMem/WPMem/MaxUpload all to 512M and Execution time to 20minutes (I’m using Laravel Forge to manage a Vultr server instance, but confirmed all of these via Site Health after a server restart).
The upload does nothing in terms of web traffic and then it goes fine until about 65% and then it just freezes (monitoring via New Relic confirmed this too). I checked the PHP, Nginx, Redis logs and there is absolutely nothing in the logs to suggest an error or any other sort of condition around the time of upload.
