2) According to StackOverflow, a recent update has also changed the default ActiveX settings in Excel to a stricter level. This disables controls from external libraries like RefEdit; we use RefEdit in our dialogs. So, in recent Excel versions, permission to use ActiveX controls must be turned on in the Excel Trust center (under File…. Options… Trust Center… Trust Center Setting). More details are in our help pages.

Chaney Ganninger at the West Virgina University is using OpenSolver to help model accelerants used in arson cases. Amazing where optimisation ends up being helpful!

Check out Chaney’s thesis:

Refinement of a thermodynamic model to explain the weathering
patterns of ignitable liquids on household substrates at elevatedpatterns of ignitable liquids on household substrates at elevated
temperatures

at https://researchrepository.wvu.edu/cgi/viewcontent.cgi?article=13611&context=etd

You might enjoy reading Adam Diamant’s article on the value of Excel for teaching MBA students:

We are pleased to announce a new release of OpenSolver for Google Sheets. This fixes bugs in the GLPK solver and NEOS-Cbc solver options which made them unavailable. These engines should now be working and available.

Errors which stopped the GLPK solver from running were related to local variables in scriptlets not being defined before Html template objects ‘glpkWorkerJs’ and ‘glpkRunnerJs’ were evaluated and ran these scriptlets. Errors such as “ReferenceError: gmplModel not defined” should now go away since local copies of these variables are initialised inside these scriptlets.

As of January 8, 2021, NEOS requires that an email address be submitted with every job. The NEOS-Cbc bug was related to this – originally we did not include a user email address in the xml file sent to the NEOS server.

Since NEOS now requires that each job contain an email address, we include the user’s email address in the xml file. This email address is only sent to NEOS when the model is being solved and only if the user selects NEOS-Cbc as the solver engine.

We have updated our privacy policy and information about OpenSolver for Google Sheets to reflect these changes.

As always, we welcome your feedback. Please comment below if it works ok, or if you encounter issues, or if you have any questions regarding the new release. Thanks!

We’ve released OpenSolver 2.9.4 for beta testing! You can download this new version of OpenSolver from: https://sourceforge.net/projects/opensolver/files/.

Below are the release notes that cover the changes made in this new version of OpenSolver:

V2.9.4 – 2021-01-15

• Extended support for special characters in sheet names
• Removed support for Satalia Solver Engine since Satalia no longer offers an online service
• Added fix for NEOS email validation
• Added support for value-seeking models with no constraints

V2.9.3 – 2020-03-01

• Added support for using Gurobi 9.0
• Added a temp fix for running consecutive operations on Excel64bit

As always, we welcome your feedback. Please comment below if it works ok, or if you encounter issues, or if you have any questions regarding the new release. Thanks!

We have implemented a fix so that OpenSolver for Google Sheets should now be accessible and working again.

It seems that some of the comments in our code were causing an OAuth scope /auth/script.scriptapps – which we do not need or use – to be detected. These comments have now been removed, so we expect error messages like “Sign-in with Google temporarily disabled for this app” to stop appearing.

We’d greatly appreciate it if you could test that it now works. Please comment below if OpenSolver for Google Sheets works for you, or if you encounter any issues, or if you have any other questions.