Bugs in Unity 2019?

Question

Unity

I worked on Unity 5.6.7 for a very long time, but I had to upgrade to a newer version (2018+) so that I could compile the game for Android with tags (64bit, App Bundle), but when I updated Yunka, when creating the scene, I began to knock out 2 errors, but no text. I can’t google because I don’t know the essence of the errors. Please help (attached screenshot).
PS Such error in any version above 5.6.7 (2017+, 2018+, 2019+)

Answer 1

GavriKos rightly said. Everything can be googled. I had the same problem and started googling. Finally found the solution on Google:

File > BuildSettings > PlayerSettings > Other > Scripting Runtime Version

there should be net4 by default, you put net3.5. After reboot yunki errors should be gone.