Something I noticed when using the 13 beta 3 version - normally I'll drag files into PL/SQL developer to open .sql or .pck files. This doesn't seem to work in the beta 3. I get a "no" icon and nothing happens.
Sorry I'm a little late responding. It seems to be working for me now, but I'm not sure what has changed. I haven't installed anything or changed anything.
1. Windows 10 Enterprise version 10.0.16299
2. 64 bit
3. Single Document