Trying to upgrade from Ubuntu 16.04 to 20.04 and I get this message:
Could not calculate the upgrade
An unresolvable problem occurred while calculating the upgrade.
This was likely caused by:
- Unofficial software packages not provided by Ubuntu Please use the tool 'ppa-purge' from the ppa-purge package to remove software from a Launchpad PPA and try the upgrade again.
Can someone tell me what I need to do, please? Thanks
Dell Latitude E6420 64-bit 8Gb 500 Gb SSD
