Sidecar is perhaps the most interesting feature launched by Apple this year for iPad devices and Mac. With Sidecar you can connect and work together on a Mac cu macOS Catalina and a iPad OS iPadOS. Is a "remote display” through which the iPad becomes a functional extension of Mac, the user can benefit from the touch screen features, Apple Pencil in applications open on Mac.
For Sidecar to work, both devices need to have compatible operating systems. macOS Catalina or newer and iPadOS 13 or newer (with the mention that both operating systems are currently in version Public Beta, following that in the autumn of this year to be launched in final version for all users).
Many users are already testing new operating systems on their devices Mac and iPad, but firstpinSidecar connection problems and errors between devices.
"You can't open the "Sidecar" preferences sorry because it is not available to you at this time. To see this preferences pane, you may need to connect a device to your computer. " or "A miscellaneous error occurred (-401)".
Possible causes of which Sidecar does not work between macOS Catalina si iPadOS
Models of Mac and iPad compatible Sidecar
Although macOS Catalina can be installed on devices launched by Apple in 2012 (MacBook 2015 or later, MacBook Air 2012 or later, MacBook Pro 2012 or later, Mac mini 2012 or later, iMac 2012 or later, iMac Pro 2017 or later, Mac Pro 2013 or newer), the Sidecar features are available only for newer models.
models Mac Sidecar compatible:
Late 2015 27″ iMac or newer
iMac Pro 2017
Mid 2016 MacBook Pro or newer
Late NEVER Mac mini or newer
Late NEVER MacBook Air or newer
Early 2016 MacBook or newer
Mac Pro 2019
Sidecar compatible iPad models:
iPad Pro - all models
iPad (6th generation)
iPad (5th generation)
iPad mini (5th generation)
iPad mini 4
iPad Air (3rd generation)
iPad Air 2
If you have one of the above iPad models (with iPadOS) and Mac (with macOS Catalina), the Sidecar feature should work smoothly.
If devices can not be connected to each other, you will need to keep in mind other requirements for Sidecar to work.
For Sidecar to work, the connection between a Mac and an iPad can be made either through Bluetooth, or using Lightning data cable or USB-C. In the case of a Bluetooth connection between the two devices should not be greater than 10 meters. For cable connections make sure they are of good quality. Preferably be original cables or MFI.
A requirement that mirroring enters iPadOS si macOS Catalina to be possible, and Sidecar functional, is that both devices to be connected to the same account iCloud.
The iPad does not appear in the list of devices AirPlay
Normally, the iPad should appear in the list of devices AirPlay from the Menu Bar. If you don't find your iPad there, go to Mac in Setting → Sidecar → click on "Devices" under "Connect to" and select your iPad.
Sidecar does not work with all applications
You can open Final Cut Pro, Adobe Illustrator, CorelDRAW, Cinema 4D or Maya pe Mac and to work through Sidecar on the iPad, using its touch screen facilities Apple Pencil. However, not all applications are compatible with Sidecar.
I would say that the big absence from Sidecar is Adobe PhotosHop. Apple Pencil turns the iPad into a real graphic tablet, and in Photoshop you could create interesting images with Sidecar.
Most likely until the fall, when the official launch is scheduled for iPadOS si macOS Catalina, other compatible applications will be added.