[Gretl-users] Gretl no longer reads panel data

Hi, Suddenly, Gretl no longer reads panel data. It stopped working today, with a file that always formed before. The error started appearing when I added a variable, but it was still there when I deleted the variable. Gretl says it discovered the first column to contain a string variable and suggests to remove it. But if I do it will no longer be panel data. Anyone else experiencing this? How do I fix it? Best, Lars