PHPP_CLI ERROR error l.135

Hi, i have a lot of errors

level : ERROR
action : error l.135
Parameters : Mailer.php
More : Message=flock() expects parameter 1 to be resource, boolean given

Pydio 8.0.2
Ubuntu 16.04 LTS
Apache 2

I think this is block watches notification but I don’t understand why.

Any idea ?

Thank you !

can you tell me when and how did you install Pydio.