When I am running all test classes button in config only sandbox I am getting below error.

Unable to Process Request Concurrent requests limit exceeded.

To protect all customers from excessive usage and Denial of Service attacks, we limit the number of long-running requests that are processed at the same time by an organization. Your request has been denied because this limit has been exceeded by your organization. Please try your request again later.

3 Answers 3


There's a number of tests that you can run in a 24-hour window. There's also concurrent limits related to using too many resources at once. Practically speaking, this means that a "run all tests" should ideally be spread out over time; run single tests whenever possible, and reserve run all tests for a system-check for code coverage, etc. You can also run into this if multiple users try to run all tests at once. Only one person at a time should be performing a run all test run. In ordinary cases, run only single tests.


It sounds like you have many long-running tests. Instead of running them all at once you'll need to run them in smaller groupings. You can experiment to see which are short vs. long-running and plan your groupings accordingly.


Reason of this error is there are multiple users login in same org and possibly from same username. Salesforce has limit to prevent excessive use.

It is part of governor limits applied to user, when many people work on same org read here and here. These limits include API calls, web interface etc..

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .