MySQL Error 1215: Cannot add foreign key constraint
Check that both tables have the same engine type, so there isn’t a mix of for example MyISAM and InnoDB.
Author Archive for: stefan
Entries by Stefan Helander
rm unable to delete file even as root or sudo [Solved]
When it is not possible to delete a file using rm even when logged in as root or by using sudo, check the file attributes with: lsattr filename.ext If it has the “i” attribute, this is preventing the file from being deleted, even by super users. When you have verified the reason for this and […]
Ispconfig3: Let’s Encrypt not working
There can be several reasons for Let’s Encrypt certificates not being issued for sites. These are some things to check: When creating a new website, save it first, then open it again and check Let’s encrypt and then save it (i.e. don’t check the Let’s Encrypt unless the website has been saved at least once […]
Roundcube – add client’s IP-address and host name to outgoing email headers
By default, the logged in client’s IP-address and hostname are not present in the outgoing email headers which makes it hard to trace the origin in case of abuse. To make roundcube add this to the email headers of outgoing email, put this in the roundcube configuration file: // put user’s ip and host name […]
Ispconfig3: awstats/webalizer not working, client web logs empty
If awstats or webalizer is not containing any data and the client web logs are empty, the cause might be missing mounts of the log directories in /etc/fstab. Search /etc/fstab for the client domain name. If no log mount is found, add a line for the client web site manually in this form: /var/log/ispconfig/httpd/DOMAIN.COM /var/www/clients/clientNNN/webNNN/log […]
Asterisk / FreePBX sip trunk registration problem, Serious Network Trouble
The asterisk log file (/var/log/asterisk/full) shows entries like this: [Sep 3 04:02:08] ERROR[3984] chan_sip.c: Serious Network Trouble; __sip_xmit returns error for pkt data Solution: The server had been moved from one public IP-address to another. In Asterisk PBX settings, the fields for both External IP and Bind Address (under Advanced) needed adjustment to the new […]
Toshiba laptop green blinking LED light
A Toshiba laptop I encountered recently was deemed “possibly dead”. It would not boot and screen was just black. A blinking green LED was present, meaning the battery is discharged. Further investigation revealed that the power supply electric cord had fallen out of the socket. Plugging it in again turned the blinking green LED to […]
Samsung SL-M3375FD scan to email and SMB stopped working
Samsung multi function laser printer SL-M3375FD could suddenly not send email (scan to email) and SMB shares stopped working. Logging in to the printer web interface, using the test function for the SMTP settings just resulted in “failed” when it tried to authenticate to the email server. Recently the email server’s SSL-certificate was updated because […]
/etc/cron.daily/amavisd-new: Please run this cronjob as user amavis
After a system update I started to receive cron messages saying “/etc/cron.daily/amavisd-new:Please run this cronjob as user amavis”. It turns out that this happens because the cron script is replaced by a new one located in /etc/cron.d and the one in /etc/cron.daily is left behind giving this error message. Solution: After checking that the new […]
Windows 10 VPN-problem after update to 1903 [workaround]
After installing the 1903 Windows 10 update, also called may 2019 update, users experience problems when trying to connect a VPN connection. The problem occurs when clicking Connect on the VPN-connection through the system tray. When the dialog box for user name and password should appear, nothing happens. Until Microsoft solves this a temporary workaround […]