Recently, after some reports of customers, I found a strange behavior.
These customers receive an internal server error page while accessing their account.
Sometimes the error occurs for each page of the site.
Investigating I found that these errors correspond to errors reported in the server's errror_log:
[Mon Jul 09 15:38:19 2018] [warn] [client ---.--.--.-- (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server [Mon Jul 09 15:38:19 2018] [error] [client ---.--.--.--] Premature end of script headers: index.php
At first I was thinking about a bad server configuration, but I noticed that to solve the problem with the account it is necessary to open the account in question in the backend and save it without making any changes.
After this procedure it is possible to log in from the frontend without any problem, at least for a certain period.
When the error occurs on all pages of the site, it is sufficient, instead, to remove the "persistent_shopping_cart" cookie from the browser to restore normal operation.
It seems that the error is only found by users with products in the shopping cart
Has anyone else encountered this problem?