Thank you, you are right!
Suddenly and without detectable reason, any access to some files of my self-hosted WordPress installation causes 403 errors. One of these files is wp-login.php.
If Force Login is activated, all requests are redirected to wp-login.php and result in an 403 error. Deactivating Force Login seems to solve the problem, but acutally it doesn‘t, it just avoids the requests to wp-login.php.
The reasons which are responsible for the 403 errors are unknown. It is neither the .htacess file nor the access rights. I did not change anything – despite the WordPress update a few hours before. I tried for hours without success. Many things work fine, sometimes things result in 403.
My installation is self-hosted and i have more WordPress installations: no problems with these. The solution comes on the same way, as the problem raises: I stopped my work and went to bed. The next day, everthing was fine again, suddenly and without detectable reason.
I found several posts, where people decribe comparable experiences. My advice: if everything fails, go to bed and hope for tomorrow.
Thank you again!
