Problem Statement/Rationale

What is going wrong? What action would you like the Engineering team to take?

Can't create a 2nd Aggregation pipeline stage.

This happens when there is no index other than the default index. After adding an index, aggregation pipeline works as normal.

Steps to Reproduce

How could an engineer replicate the issue you’re reporting?

Using sample_mflix on standalone mongod.

Create pipeline on $match using
{    year: {$gte:1950}
}

Click "Add Stage" button.

See error, "An error occurred while rendering AggregationsPlugin: Cannot have two HTML5 backends at the same time."

Expected Results

What do you expect to happen?

Can create a 2nd aggregation pipeline stage.

Actual Results

What do you observe is happening?

See error, "An error occurred while rendering AggregationsPlugin: Cannot have two HTML5 backends at the same time."

Can't go back to previous screen either.

Additional Notes

Any additional information that may be useful to include.