0x001703EE : read error or meta-data is corrupted / Acronis cloud with TrueImage 2013 build 6514

Sorry for the subject that is maybe not exactly the right message because my Acronis version is in French.

I've been using the Acronis Cloud service to save data for 3 PC's almost for almost one year. The biggest storage (100 GB) is used by a PC for which Acronis Cloud has not been working for the last 2 weeks. From the TrueImage 2013 log file, I get (in French) :
Erreur de lecture ou le contenu des métadonnées est corrompu.
Code d'événement : 0x001703EE

Which means read error or metada is corrupted.

I've seen a similar problem using Google but it was related to the fact that the storage quota was exceeded which is not my case (100 GB left on my cloud storage)

By the way, if I try to open the Acronis Cloud repository over the Web ( https://cloud-wr-eu1.acronis.com/index.htm ) I get the following error :

Impossible de lire les métadonnées de la sauvegarde. Veuillez contacter l'équipe d'assistance technique.
ssn: 360E97973..... 6876ADF.alpha (I removed some characters because don't know if it is a good idea to publish this key)
rqst: 3.... 5846
date: décembre 11, 2013, 20:11:08 (UTC)

Strange is that 2 days ago, the 2 other PC's using Acronis Cloud were available and it was possible to browse the content using the web interface. Today, I've not checked if the backup for such PC' is still working but the web access returns the mentioned error directly. So, no way to browse the content for any of the 3 PC's. Everything is stuck.

Can someone help ?

Many thanks.
Thierry