I see. Thankfully the workaround is fairly simple...
B4X:
.....
Dim UploadFileSize As Long = File.Size(MyFilePath,MyFile)
.....
Sub FTP_UploadProgress (ServerPath As String, TotalUploaded As Long, Total As Long)
'varTotal is corrupt use UploadFileSize instead
ProgressBar1.Progress = TotalUploaded/UploadFileSize *100
End Sub