ModSecurity: XML: Unable to evaluate xpath expression

Hey everyone!

I got a really big error log file (94MB) filled with the messages bellow repeated every 30 seconds. It seems it have been pilling up trough months, but since everything seemed to be working fine I didn’t noticed until earlier this week when I updated to v11 and by chance took a look at the logs.

A fragment from today:

[Thu Jan 05 19:27:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:28:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:28:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:29:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:29:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:30:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:30:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:31:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:31:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:32:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:32:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:33:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:33:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:34:06 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/carddav/addressbooks/myusername/contacts/"]
[Thu Jan 05 19:34:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:34:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:35:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:35:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:36:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:36:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:37:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:37:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:38:21 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]
[Thu Jan 05 19:38:51 2017] [error] [client 111.222.33.444] [client 111.222.33.444] ModSecurity: XML: Unable to evaluate xpath expression.  [hostname "cloud.mydomain.me"] [uri "/remote.php/webdav/"]

This was originally an OwnCloud installation that I migrated to Nextcloud 9, then updated to 10 and recently to 11. Judging by the dates I can say that the error happened even when it was Owncloud 8 and 9.

I’m using Liquidnet’s shared hosting, running:

PHP 7.1
MySQL 5.6.27
Accessing over regular Http

Applications enabled, aside from default are: Calendar, Tasks and Contacts.

I haven’t noticed any malfunction on the day to day use aside from a (maybe unrelated) high server CPU usage and this definitely not normal huge error log.

I’m just a power user, but know the old art of google-fu if you guys can point me in the right direction.

Cheers.