not worked until changes in permalink settings

Hello,

– my permalink setting was: /%postname%.php
– i installed the plugin
– set it to: .php
– it was “integrated”, means: the pages had the .php extension e.g. in the menues etc.
– but when loaded one of these pages it was blank (html source was just a single character: “1”)
– edited on of these pages (maybe it has to somehow being saved/set afer the plugin was there?) and changed the filename
– it reflects in e.g. the menues with the new filename and with the .php extension
– but when refreshing/loading the page it was still blank
– when gone to the permalinks settings and deleted the setting for the category base (there was one)
– reloaded the page: all fine
– gone to permalinks settings and reentered the category base (te reproduce the error)
– reloaded the page: all fine
– so: cant reproduce the error, what ever i change in permalinks settings page

Dont know how and why. But the pages have been blank after i installed the plugin. It all went ok after i have made a change in permalinks settings. And the error has not come back.

It was a new and very clean wordpress installation. Just two pages, no posts, standard theme. Only these plugins have been installed: yoast seo, live composer and a captcha plugin.

Not sure what has it fixed. But all changes within the wp-installation and settings hadent done it, until the edit of peramlinks settings. And afterwards all further permalinks settings hadent brought the error back.