ADB.exe is obsolete and has serious performance problems

Solution 1:

I am new to android as well. dkalev's answer is correct but not very descriptive for a new user. I have outlined the steps below.

1. Double Shift to open the search box
2. Type SDK Manager
3. In the results shown click "SDK Manager"
4. In the window that opens click the second tab "SDK Tools". You should see that there is an update available for SDK Build-Tools on the first line
5. Check "Show Package Details" in the lower right hand corner
6. Scroll to the last (latest version) item under "SDK Build-Tools" and check the box. (Mine was 28.0.1)
7. Click "Apply"
8. In the dialogue box that pops up, click "OK"
9. When the installer finishes, click "Finish"
10. Uncheck "Show Package Details" and look at "Android SDK Build-Tools" (first line). There should be no update available and it should say "Installed"
11. Click "OK" to close the SDK Manager

Solution 2:

For me, update SDK doesn't help. I solve this problem by unchecking the emulator option "Use detected ADB location". Give it a try.