No permission to access /wp-admin/upload.php

Dear all.

I get the following 403 error:

Forbidden
You don’t have permission to access /wp-admin/upload.php on this server.

This happens when I want to reconnect some pictures to a posting (when the initial relation is not existing). I always need to rename the .htaccess file, then doing my changes and rename back to .htaccess. So I assume that something is blocked from .htaccess. What need to be done to not use this work around?

Wilhelm

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