Identify and Systematically Fix GAEB Errors
Your GAEB file won't import, shows wrong values, or gets rejected by the client? Find the most common problems here with concrete solution steps.
Encoding and Character Set Problems
The most common error in GAEB files relates to character encoding. GAEB DA XML requires UTF-8 encoding, but many older systems generate files in ISO-8859-1 or Windows-1252. This leads to unreadable umlauts and can block the import completely.
Symptom: Umlauts Display as Special Characters
Solution: Open the file in Notepad++, select Encoding → UTF-8, and save again. Also check the XML header: it must contain encoding="UTF-8".
Symptom: Import Fails with 'Invalid Character'
Solution: The file contains invalid control characters. Use an XML validator to find the exact position and remove the character manually.
Symptom: BOM Marker Causes Errors
Solution: Some GAEB files have a UTF-8 BOM (Byte Order Mark) at the file start. Remove it with a hex editor or in Notepad++ under Encoding → 'Convert to UTF-8 without BOM'.
Version Incompatibilities
GAEB exists in several versions that are not all compatible with each other. The three main versions — GAEB 90, GAEB 2000, and GAEB DA XML 3.x — differ fundamentally in structure and capabilities.
Symptom: 'Invalid GAEB Format' on Import
Solution: Check which version your software expects and which version the file uses. Older software often only supports GAEB 90 (DA81/DA83). Update your software or ask the client for a compatible format.
Symptom: Positions Missing After Import
Solution: Some positions use extensions only available in newer GAEB versions. Check if your software supports the full specification of the delivered GAEB version.
Symptom: Long Texts Not Displayed
Solution: In GAEB DA XML, long texts can be embedded in HTML or plain text format. Older software ignores HTML-formatted long texts. Export texts separately or use a current software version.
Structural Errors in the Bill of Quantities
Errors in the bill of quantities structure are often hard to find because the file is technically valid but contains incorrect content. These errors only surface during calculation or review.
Symptom: Duplicate Position Numbers
Solution: Check the file for duplicate item numbers (OZ). Some AVA programs automatically renumber duplicates — but this can cause confusion with assignment. Clarify with the client.
Symptom: Quantities Missing or Zero
Solution: Some positions are intentionally set as provisional items (quantity 0) or alternative positions. Check the position type (standard, provisional, alternative) in the attributes.
Symptom: Hierarchy Is Inconsistent
Solution: Titles and sections must form a logical tree structure. If positions sit outside sections or nesting is inconsistent, notify the client about the error.
Rounding Differences and Calculation Errors
GAEB doesn't define rounding rules unambiguously, leading to differences between software solutions. These differences are usually small but can become significant with large bills of quantities.
Symptom: Position Total Doesn't Match UP × Quantity
Solution: Check your software's rounding rule (commercial, mathematical, 2 or 3 decimal places). Adjust settings to match the client's requirements.
Symptom: Grand Total Differs Between Software Products
Solution: The rounding sequence (sum first then round vs. round first then sum) affects the result. Always use the same software the client uses for submission.
Symptom: Discount Is Calculated Incorrectly
Solution: Check whether the discount applies to individual positions or the grand total. GAEB allows both methods — the tender documents should specify this.
Import and Export Problems
Errors during GAEB file import or export often have technical causes that can be resolved with the right settings.
Symptom: Import Takes Unusually Long
Solution: Large GAEB files (>10 MB) with thousands of positions can import slowly. Check if embedded images or documents inflate the file size. Remove attachments that don't belong to the bill of quantities.
Symptom: Exported X82 File Gets Rejected by Client
Solution: Ensure your export version matches the import version. If the client sent X81 in GAEB DA XML 3.2, your X82 export must use the same schema.
Symptom: Attachments (PDF, Images) Lost During Import
Solution: Not all software supports embedded attachments in GAEB files. Check if attachments were delivered as separate files and import them manually.
When to Contact the Issuing Authority
Not all GAEB problems can be solved on your end. In the following situations, contact the client or issuing authority — preferably in writing with a concrete error description.
The GAEB File Is Not Valid
If a GAEB validator reports structural errors not caused by your software, the original file is faulty.
Positions Are Contradictory
If service descriptions contradict the specified quantities or units, the client must clarify.
The Required GAEB Version Is Outdated
For public tenders, at least GAEB DA XML 3.2 should be required. If only GAEB 90 is accepted, this may limit capabilities.
Frequently Asked Questions
Why won't my GAEB file open?
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Most common causes: (1) Wrong extension — e.g. .x83 for a D83-format file. (2) Your AVA software doesn't support the schema (GAEB-DA-XML 3.3). (3) The file is corrupted or incomplete — visible as an XML parse error. Check extension first, then schema version, then ask the issuing authority for a corrected copy.
How do I fix 'Invalid quantities' errors in a GAEB file?
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This appears when quantity fields are empty or negative. In an X81 (tender publication) empty quantities are normal — you fill them as bidder. In an X83 with missing quantities the source file is faulty; request a corrected version before pricing.
What does 'Schema version not supported' mean?
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Your software reads only older GAEB versions (e.g. GAEB-90 or GAEB 2000) but the file uses current GAEB-DA-XML 3.3. Fixes: update the software, use a GAEB converter (AVA vendors offer free tools), or ask the issuing authority for the older format.
How do I detect a corrupted GAEB file before pricing?
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Three quick checks: (1) File size — a valid bill of quantities is usually 50 KB to several MB; under 5 KB is suspicious. (2) XML validation in an online validator. (3) BlackSwanAI parses the file and flags missing required fields, inconsistencies and incomplete position blocks automatically.
What if optional items (Bedarfspositionen) are missing from the GAEB file?
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Optional items aren't always marked as such in the bill of quantities. If your software doesn't recognise them, check the XML <Marker> tag on each position. If the marker is missing, the software treats the position as standard — risking surprises if quantities shift. When in doubt, ask the issuing authority.
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