I have been working with my files for a while, but when I tried to open them this mornig nothing is showing up except for the sheet border, however when I hover the mouse over the sheet tab and also in the preview window before opening the drawing the items on the sheet show.

Can someone tell me how to adjust  or fix this issue, please?  I am still faifly new at this and am not experienced enough to troubleshoot.

Thanks for any help given,

Martin