Recently I encountered an issue where PhpMyAdmin could not export data. After clicking export, there was either a request failure or a blank page. After refreshing, it reported an error:
export.php: Missing parameter: what (FAQ 2.8)
export.php: Missing parameter: export_type (FAQ 2.8)
According to online resources, it was finally determined that the php.ini settings needed to be adjusted.
My original setting was post_max_size = 8M, and increasing it to post_max_size = 20M fixed the issue.
I haven't deeply examined the PhpMyAdmin source code, but I estimate that there are dependencies on the aforementioned PHP environment values in the program, and this value needs to be relatively large for proper operation.
Original Link: https://www.snowpeak.fun/cn/article/detail/a_solution_to_phpmyadmin_cannot_export_data/