You can transfer files by exporting them using the "Export to local Gantter file..." option in the "Project" menu of the Gantter editor and then import using the "Import local Gantter file..."
The files saved in Gantter for Google Drive and Gantter Cloud are separate. So, if you log into one edition, you will not see the files you have saved in the other edition.
However, you can export to download the file and then import if you want to transfer the files to a different account or different edition.
Please try the following workaround to import your Microsoft Project file:
1. Save the file as an XML file in Microsoft Project
2. Import the XML file into Gantter using the "Import from MS Project..." option in the Project menu of the Gantter editor.
