Others IT Support

Solved : Connection error of Collabora Online “Failed to add session to XXXX”

After I updated Collabora Online, I got an error and couldn’t open office files on NextCloud.

The error is like below.

WRN  Waking up dead poll thread [HttpSynReqPoll], started: false, fin
ished: false| net/Socket.hpp:725
ERR  #30: Read failed, have 0 buffered bytes (EPIPE: Broken pipe)
ERR  #30: Socket write returned -1 (EPIPE: Broken pipe)
ERR  loading document exception: WOPI::CheckFileInfo failed:
ERR  Failed to add session to [
php/apps/richdocuments/wopi/files/52797_ocic20zydkap] with URI [
en_ttl=0]: WOPI::CheckFileInfo failed:

This「Failed to add session to」is shown when Collabora online failed to connect NextCloud server. Most cases, it’s a problem of DNS. So set-up DNS like modifying “/etc/hosts” works most cases. But this time the DNS setting was correct.

As it turns out, disabling IPv6 worked successfully.

For various reasons, the programs on my server that LISTENs the port was configured to enable only IPv4.

I didn’t know why, but I thought Collabora was trying to connect to NextCloud over IPv6 after updating.

So enabling IPv6 on NextCloud server setting might work too.

FYI, The below command temporarily disable IPv6 on Ubuntu 22.

sysctl -w net.ipv6.conf.all.disable_ipv6=1
sysctl -w net.ipv6.conf.default.disable_ipv6=1
sysctl -w net.ipv6.conf.lo.disable_ipv6=1

The below is permanently disable IPv6.

vi /etc/sysctl.d/60-custom.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

sysctl -p
systemctl restart procps