Obscure Solver Error Conditions

This page covers a few Solver error messages which are possible, but very unlikely to appear with recent versions of Microsoft Excel and PCs which are of fairly recent vintage. They are included for the sake of completeness.

Hardware error: Unexpected floating point exception (probable math coprocessor fault). Please contact your hardware vendor.

This message appears if certain unexpected floating point exceptions occur while the Solver is performing its calculations. The only known case where this can occur is in certain older models (prior to 1992-93) of 80387-compatible math coprocessor chips. If it appears, you may have to replace your math coprocessor in order to use the Solver on this model.

Solver: An unexpected internal error occurred, or available memory was exhausted. Please verify that your model is correctly entered and all cells contain numeric values.

This message appears if Microsoft Excel detects an error during the Solver's execution which is not otherwise provided for by the Solver. A likely cause is a cell range referenced in the Constraint List Box which has been removed from the worksheet by deleting rows or columns. For more information, consult Known Problems in Microsoft Excel Solver.

Solver interrupted; choose Formula Solver to resume.

This message is very unlikely, but may appear if you press ESC or take a similar action to interrupt the execution of Excel macro code at an instant when the SOLVER.XLA code has begun executing but has not yet trapped the ESC key. "Formula Solver" is a reference to the menu choice used to activate the Solver in Excel 4.0, which became "Tools Solver" in Excel 5.0 and later versions. Simply re-run the Solver and be careful about pressing the ESC key!

Copyright © 1996 Frontline Systems Inc.
Last modified: December 01, 1996