Error Upgrading OJS to

Hi guys,

I was running the upgrade process in a big OJS 2 portal and during our upgrade process from OJS 2.4.8-2 to 3.1.1-4 in the step

[code: Installer Installer::convertSupplementaryFiles]

we got this error:

PHP Fatal error: Call to a member function getStatus() on null in classes/install/ on line 1354

any help would be useful, because the process is taking about 2h till it reach this stage.