Not opened for read

I recenly bought a licence for this CAD software.
I am trying to meke the transition form ACAD.

I have drawings in dwg, made by a third party software (licenced by my supplier)

On these drawings I am unable to take any actions. Not even draw a line!

I ge the message : "Not opened for read"

Any tips?

Re: Not opened for read

I got exactly the same message.

It is not message box, see the log below:

File Version: R21 (2007) release
Command: CIRCLE
Not opened for read
Command: LINE
Please pick a point, or choose from the list:
Invalid input
Command: ARC
Invalid input
Command: PLINE
Not opened for read
Other non-entity-creator commands wokrks