Flight was rescheduled, now I can't make connection (flights have been booked together, same airline)

Question

A couple of months ago I booked a flight from Managua (Nicaragua) via Houston, Texas to Munich (Germany) on United Airlines. The date of the flight is more than four weeks ahead.

Today I received an email notification that the first flight has been rescheduled. The flight from Managua arrives in Houston at 5.20 pm while the connecting flight from Houston to Munich is leaving at 2.30 pm, the same day. Therefore I will obviously miss the flight.

In the email it is written:

We apologize for any inconvenience this may cause. Rest assured that your reservation remains valid, and if you do not wish to make additional changes, no action is needed based on this email

This seems ridiculous, as I have to make additional changes:

So my questions are:

• Is this standard procedure? Just sending an email notification without call to action even though the flight plan became inapplicable?
• What are my options here?
  • Can I step back from the flight?
  • If they offer me another itinerary which is inconvenient for me (e.g. more layovers) and I book a flight with another airline, will they refund the cost?

Update(04.06.2018):

I researched alternative flights and found one flight from Liberia (North of Costa Rica) which suited me as well. (I guess Nicaragua is right now not the best place to be anyway)

Then I called United Airlines about the issue. Their first offer was to take the plane in Houston one day later and providing an hotel voucher. When I proposed to fly from Liberia they first claimed the additional costs. But after some discussion the flight was changed free of charge.

Answer 1

It's likely a mistake. Call the airline and they should be able to correct it, and offer you a new itinerary that is actually possible.

Standard procedure when an airline changes their schedule is that they will update your whole itinerary, rebooking following flights as needed, to get you to your final destination. That didn't happen correctly in this case, which is probably an error on their part. It isn't normal.

(In some cases, e.g. if the airline is going to stop serving a city entirely, they might unilaterally cancel your reservation without offering you a new itinerary, and refund your money. But that doesn't seem to be the case here.)

If the new (possible) itinerary doesn't fit your travel plans, you should have the option to cancel the whole booking and get a full refund. Since this flight goes to the EU, it's possible you might be eligible for additional compensation as well; maybe someone more familiar with EU rules can discuss this.