How to Fix calcChain.xml Errors in Excel

The workbook has two sheets, with sheetId 1 and 2, but chain entries name sheets 3, 4, 5, and 7. This happens when a sheet is deleted, or a workbook is assembled by a tool that does not rewrite the chain. One bad entry and several bad entries are the same problem.

<!-- workbook.xml: the only sheetId values are 1 and 2 -->

<!-- CalcChain_InvalidSheetReference -->
<c r="A1" i="1"/>
<c r="B1" i="4"/>   <!-- ← CORRUPT: no sheet has sheetId 4 -->
<c r="C1" i="1"/>

<!-- CalcChain_MultipleInvalidReferences -->
<c r="A1" i="1"/>
<c r="B1" i="3"/>   <!-- ← CORRUPT -->
<c r="C1" i="1"/>
<c r="D1" i="5"/>   <!-- ← CORRUPT -->
<c r="E1" i="7"/>   <!-- ← CORRUPT -->
<c r="F1" i="1"/>

Fix: For each bad entry, confirm which worksheet actually contains the formula and look up that sheet's sheetId in workbook.xml. Only then correct the value. If you cannot prove which sheet an entry belongs to, delete that entry. If many entries are wrong, use the rebuild method below rather than editing them one by one.

<!-- Fixed: invalid entries removed (or corrected to a real sheetId) -->
<c r="A1" i="1"/>
<c r="C1" i="1"/>
<c r="F1" i="1"/>

The r attribute must be a real cell address. A worksheet has at most 1,048,576 rows and 16,384 columns (A to XFD), so an address outside those limits cannot refer to any cell.

<c r="A1" i="1"/>
<c r="B2000000" i="1"/>   <!-- ← CORRUPT: row 2,000,000 is past the last row (1,048,576) -->
<c r="ZZZZZ1" i="1"/>     <!-- ← CORRUPT: column ZZZZZ is past the last column (XFD) -->
<c r="C1" i="1"/>

Fix: Delete the entries whose address is impossible. If a valid-looking address is wrong rather than impossible, open the worksheet XML and check whether the cell actually holds an <f> formula before deciding to keep it.

<!-- Fixed -->
<c r="A1" i="1"/>
<c r="C1" i="1"/>

When a save is interrupted, or a tool writes the chain badly, an entry can be left unclosed. A chain that does not parse cannot be trusted, and a hand-reconstructed one could silently skip formulas.

<calcChain xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
    <c r="A1" i="1"/>
    <c r="B1">
    <c r="C1" i="1"
                   <!-- ← CORRUPT: B1 is never closed, C1 has no "/>", and </calcChain> is gone -->

Fix: Do not try to patch a malformed chain. Delete the part and let Excel rebuild it, using the steps below. The formulas themselves are in the worksheet XML and are not affected.

The chain file exists but contains no entries at all. The workbook still has formulas (=SUM(A1:A5) in Sheet1!A11), so an empty chain describes nothing and does not match the sheet. The schema expects a chain to list at least one cell, so an empty one is invalid rather than harmless.

<calcChain xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
  <!-- ← CORRUPT: no <c> entries, but the workbook has formulas -->
</calcChain>

Fix: Either restore the entries (here, <c r="A11" i="1" l="1"/>) or, more simply, delete the chain and let Excel rebuild it.

Corruption rarely stays in one part. Here the chain names a nonexistent sheet and styles.xml has a second cell format that refers to a font that does not exist. Fixing only the chain leaves the file broken.

<!-- calcChain.xml -->
<c r="A1" i="1"/>
<c r="B1" i="4"/>   <!-- ← CORRUPT: no sheet has sheetId 4 -->

<!-- styles.xml: only one font exists (fontId 0) -->
<cellXfs count="2">
  <xf numFmtId="0" fontId="0" fillId="0" borderId="0" xfId="0"/>
  <xf numFmtId="0" fontId="999" fillId="0" borderId="0" xfId="0"/>
  <!-- ← CORRUPT: fontId 999 does not exist -->
</cellXfs>

Fix: Repair the two parts separately. For the chain, remove the bad entry or rebuild the chain. For the style, either point the format at a font that exists or delete the extra <xf> and put the count back. See Fix styles.xml for the full set of style repairs.

<!-- Fixed: styles.xml -->
<cellXfs count="1">
  <xf numFmtId="0" fontId="0" fillId="0" borderId="0" xfId="0"/>
</cellXfs>