After an EDIT of a SIMPLE NOTE, in the recently installed DS2015 (64bit), the only way  to resume drawing is by means of  a REBUILD command.

Performance as follows:

1) select one simple text;

2) right click select Edit;

3) change text;

4) enter or right click (without effect -> cursor only available in command line and properties area);

5) type REBUILD or REGEN;

6) carry on.

Note: I installed Draftsight64.exe (156.011.872 bytes) without uninstalling Draftsight32-4.exe.

           May be I should not have done it that way ?