Unable to Edit Drawing

Hi,

I have been using Draftsight for a while now after using ACAD for a number of years. I cannot edit/delete/Modify in any way a drawing i had been working on, I worked on this last night and have now come in this morning and found this issue, i assume i have done something without knowing, i can't edit any drawings at all now.

I have used one of my collegues PC and have been able to change the drawings on there, so I'm assuming this is a setting issue?

Please help??

 

Thanks, Craig