Please help...i have this error

Error:Execution failed for task ‘:app:preDebugAndroidTestBuild’.

Conflict with dependency ‘’ in project ‘:app’. Resolved versions for app (26.1.0) and test app (27.1.1) differ. See for details.

Well, have you read that link? :upside_down_face:

To resolve this issue, simply make sure that you use the same version of each dependency that is common to both your app and its instrumented tests.