When I try to run my Android project on Eclipse ADT, I see this in the Console:
[2017-03-24 15:34:41 - Dex Loader] Failed to load C:\Users\jaimemontoya\android-sdks\build-tools\26.0.0-preview\lib\dx.jar
[2017-03-24 15:34:41 - CouponClub] Unknown error: Unable to build: the file dx.jar was not loaded from the SDK folder!
I am using Eclipse Neon.2 Release (4.6.2):
This is the package configuration I have as seen from the Android SDK Manager:
What I understand from that error is that it failed to load dx.jar because it is trying to load it "from the SDK folder". The message even uses an exclamation mark to say that! What SDK folder is it referring to? I thought in this case "C:\Users\jaimemontoya\android-sdks" would be considered an SDK folder. Do you know where it is expecting to find the "dx.jar" file?
None of the answers helped me only my decision fixed the situation:
Fix is to copy
android-sdk/build-tools/25.0.3/lib
to the folder
android-sdk/build-tools/26.0.1/lib
Now all works great!