What does HRESULT 0x80080011 (MEM_E_INVALID_SIZE) mean?

MEM_E_INVALID_SIZE

MEM_E_INVALID_SIZE means that the storage or allocator rejected a requested block/stream allocation because the size exceeds its representable or supported range.

Start with the failing layer

Structured-storage failures are best investigated on a byte-for-byte copy. Sector ownership, FAT or miniFAT links, stream sizes, commit state, and the file hash belong in the same record; opening and resaving the only copy can destroy the allocation pattern that identifies the writer defect.

E_OUTOFMEMORY can occur for an otherwise valid size; MEM_E_INVALID_SIZE means the requested size itself is outside the accepted contract.

Preserve before retrying

• Requested byte count before narrowing or alignment
• Integer type, multiplication/addition operands, sector rounding, and overflow checks
• Storage format limits and current stream/store size
• Whether the request comes from corrupt metadata or legitimate unusually large input

Three useful comparisons

1. Reproduce with values immediately below and above the documented limit.
2. Perform checked arithmetic in the caller and log the pre-alignment size.
3. Test the same logical data with chunked writes if the interface supports them.

A defensible fix

Apply the smallest change that addresses the first rejected condition: Validate arithmetic and format limits before allocation, reject corrupt length fields, or split the operation without changing data ordering.

Close the incident only when boundary tests pass at the maximum supported size, fail cleanly above it, and never wrap to a smaller allocation.

Technical references

The details above are grounded in the following Microsoft specifications and API documentation:

• Microsoft Open Specifications: HRESULT values.
• Microsoft: Structured Storage.
• Microsoft: IStorage.
• Microsoft: IStream.