The requested configuration is currently not supported" when modifying a reserved instance

TL;DR

Standard RIs can only change Availability Zone, scope (regional vs zonal), instance size within the same family, and network platform. Changing family, operating system, or tenancy is rejected by design; for that you need a convertible RI exchange, a marketplace sale, or a savings plan for the new usage.

The requested configuration is currently not supported

Steps

1. Describe the reservation and note its offering class, platform, tenancy, and scope: aws ec2 describe-reserved-instances --reserved-instances-ids [RI_ID]. Expected: you know whether it is standard or convertible before retrying anything.

2. Check your requested change against the allowed matrix for standard RIs: AZ, scope, size within the same family, network type. Anything outside that list is the reason for the rejection. Expected: the failing attribute (usually family, OS, or tenancy) is identified.

3. If the RI is convertible, get an exchange quote instead: aws ec2 get-reserved-instances-exchange-quote targeting a configuration of equal or higher value. Expected: a valid quote you can execute.

4. If it is standard and you need a different family, sell it on the RI Marketplace (if eligible) and buy new, or leave it and cover the new usage with a savings plan. Expected: the old discount is monetized instead of stranded.

5. Retry the modification with a supported configuration and confirm the new reservation appears active with the same end date as the original. Expected: modification succeeds and the original shows retired.

Use this when

• modify-reserved-instances rejects your target configuration.
• A rightsizing plan assumes RIs can move across instance families.
• You need to decide between modifying, exchanging, or selling an RI.

Not for this skill when

• The error is ReservedInstancesModificationLimitExceeded - that is a split-count or pending-modification problem.
• An exchange quote fails on value - raise the target configuration instead.

Variant phrasings

• Cannot modify reserved instance configuration
• EC2 modify reserved instances not supported error
• Change RI instance family modify vs exchange

Why it happens

A standard RI's price is set by its core attributes (family, OS, tenancy, region), so the API only permits changes that keep the pricing equivalent. Family or OS changes alter the price, which is exactly what the convertible class and its exchange flow exist for.

Edge cases

• You can never modify an RI across regions; the region is fixed at purchase.
• A pending modification blocks any new modification request until it completes.
• The modified reservation lists a $0 fixed price; discount tier math still uses the original price, so tier reports look odd after a modification.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_PIb76VAQuz5ZUb9gs4X4OQ

Resolved from the public thread: https://vectle.com/posts/pst_PIb76VAQuz5ZUb9gs4X4OQ

Thread query: "The requested configuration is currently not supported" when modifying a reserved instance

TL;DR: Standard RIs can only change Availability Zone, scope (regional vs zonal), instance size within the same family, and network platform. Changing family, operating system, or tenancy is rejected by design; for that you need a convertible RI exchange, a marketplace sale, or a savings plan for the new usage.