Signification of an error message

[LaurentR2D2]

Hello,

What is the meaning of this error message while doing a backup of my server ?

Cannot pack theme for vendor adminSTDOUT

Should I worry about the integrity of the backup ?

Plesk 12.0.18

Server OS : Debian 7.8

Thank you

 

[IgorG]

I suppose that this message may be related to Web Presence Builder (Sitebuilder) theme.