Problems with SAP BO 4.2 migration from BOXI3.1 with Upgrade Management Tool

Hi,

We are trying to perform an upgrade from BOXI3.1 to BO 4.2. I have created a BIAR file with BOXI3.1 Import Wizard.
The BIAR file seems to have al the exported objects. We have examined the Businessobjects.xml of the BIAR file an it includes a lot of <infoobject> tags.

However, when we import the file with thw Upgrame management tool, (via command, since we are in Linux), the result of the import is the following
(seeming that there are no objects in the BIAR):

The upgrade management tool will now perform a full update.
Opening BIAR file ...
Starting the session in the destination CMS ...
Opening BIAR file ...
Consulting the source system in search of objects that require parameters ...
100%
Preparing objects recovery ...
Retrieving objects ...
0
The step "Preparing objects" has been started.
Preparing 0 objects. Preparations:
100%
Step completed.
0 of 0 objects tried. 0 have failed.
The step "Updating objects" has been started.
Updating 0 objects. Updated:
0
Step completed.
0 of 0 objects tried. 0 have failed. 0 created objects. 0 executed objects.
The step "Committing objects" has been started.
Committing 0 objects. Committed:
100%
Step completed.
0 of 0 objects tried. 0 have failed.
The step "Updating confirmed objects" has been started.
Updating confirmed objects. Updated:
0
Step completed.
No object requires updating.
The update record can be found at: /tmp/log/LogFileUMT-20180801.csv
The tracking logs can be found at: / app / SAPBO42 / sap_bobj / logging /

So, no objects are imported, but no error is thrown.

Do you know what is happening?

Thanks,

Jose Manuel.