Sergio,
The reason you have the error is because the Tool and the WorkObject are not defined on your controller.
Either on the virtual or real machine, so these must be defined in order for the robot to recognise them. The fact that the program calls these 2 entities and they are not declared, raises the errors.
I prefer to define the tool & workObject on the controller and run my programs. This is the way we use machine tools and so I prefer to run robots this way too.
I suggest you open C:\Program Files\Autodesk\Autodesk PowerMill Robot Plugin 2020\Help
Open "PowerMill Robot - Training Manual.pdf"
Page 29 - Tool Database
Page 31 - Fixture Offsets
This contains explanation of what you are looking for.

We have the option to write out in the main file (Autodesk.MOD) the Tool & WorkObject definition.
This means the post processed file will have the XYZ Q1Q2Q3Q4 of each defined on the top of the file. This is very handy but can cause issue if not used correctly, it can cause errors on the robot or collision. If the tool defined has a position and/or orientation that does not match powermill expect something to go wrong.
Normally WorkObject is defined on the robot by 3 points, just define the name of the workObject same as in PowerMill.
Open the Fixture Offset tab (Robot configuration menu), select appropriate workplane/option and tick "Write fixture Offset data into the Robot program", this creates the WorkObject definition.
To define the Tool you have a few options (only 2 and 3 write define the tool in the output files):
1 - enter the tool and work object data manually(XYZQ1Q2Q3Q4), this is done either on the controller or the robot.
define the correct option (option 1) on the robot configuration menu (tool database menu) and post process.
Use the workplane calculator to get the correct XYZ Q1Q2Q3Q4 for each.
2 - complete the tool & spindle calibration procedure
define the correct option (option 2) on the robot configuration menu (tool database menu)
select where the tool length is coming from, and post process.
This option will write tAutodesk1 data.
3 - use the workplane calculator (steps in image on manual) to populate the tool list, save
Post process, this option will write tAutodesk1 data.

End result of tick "Write fixture Offset data into the Robot program" and using option 2 & 3 of tool database is below.

When I run jobs on robots I define the workObject on the part by 3 points (using the robot), and use option 1 of tooldatabase. I conduct a tool & spindle calibration and use the tool gauge length to define the Tool XYZ Q1Q2Q3Q4. I enter the Tool data manually into the controller, I find it safer and easier to avoid mistakes.
I hope this helps solve your issue
Alex
Alexandre Pinto
Process Specialist