Error : "unpack(): Type V: not enough input, need 4, have 0"

Hi everybody,
I have Nextcloud with a wordpress site on a server and I have an error in the log file that I can not solve, nor to find information:
{“reqId”:“WMkuHgoAAaEAAAM2DyAAAAIY”,“remoteAddr”:“X…Xx.Xx.Xx”,“app”:“PHP”,“message”:“unpack(): Type V: not enough input, need 4, have 0 at /www/wp-content/plugins/wordfence/vendor/wordfence/wf-waf/src/lib/storage/file.php#318”,“level”:3,“time”:“2017-03-15T12:05:50+00:00”,“method”:“PUT”,“url”:"/cld/remote.php/dav/addressbooks/users/PtLutin/Rep/C76F744C-2D30-0001-CB61-C710CA815CE0.vcf",“user”:“PtLutin”,“version”:“”}

This message appears 5 times per second in log, changing only .vcf file since many days. My log file is full of this error.
I do not know where the error may come from or what information you might need to help me.

Thank you in advance.

Is this path a NC setup? You retrieve contacts from NC via carddav?

Yes, it’s in the log of Nextcloud. This morning the log was 19Mo and now it’s 24Mo. I don’t know why !!!
The carddav is synchronized with Thunderbird on my pc. This synchronization works without problems.

There is no file.php with the unpack() command:

That is part of the problem. I do not have the level required to search in the NC or Wordpress codes.
This is an error written in the log Nc (level 3), by the carddav of NC, but with a Wordpress origin.
It’s been a few months since I have NC with Wordpress, before it was Owncloud, this error has grown since the last update.
I do not think it creates a security problem, but it is a problem anyway.

I don’t really understand how you installed this together and why you get references to wordpress code in your error log. One reference is this wordfence plugin, did you try to disable it? Perhaps it is not properly installed? Do you access from Nextcloud to wordpress or the other way round?

I installed Nextcloud in a directory next to the Wp directory. And I do not understand why since the update, wordfence seems to filter the webdav connection to Nextcloud and generates these lines in the Nextcloud logs.
I tried to modify the filtering rules of wordfence, without result.