The result of a conversion or arithmetic operation is either too large or too small.

An overflow or underflow, or an out-of-range value converted to a date/number.

Why it happens

• Converting a very large integer to DateTime (a bad date serial).
• Arithmetic overflow, or division producing an out-of-range result.
• A 0 or huge serial in a column being coerced to Date.

How to fix it

1. Guard ranges and use DIVIDE for safe division.
2. Validate date columns before converting — check for 0, negatives, or values far outside a sane range.
3. Cast to the correct type in Power Query rather than in DAX.