• The tool will start to run.

By Greg Harvey. Office Add-ins aren’t the only ones that you can use to extend Excel 2016’s built-in features in some way. You can also use built-in add-ins created by Microsoft or third-party Excel add-ins that you can purchase from a wide variety of vendors.

Do not open.vsto files manually Do not attempt to open the Macabacus.vsto files located under the Program Files folder in an effort to force the Macabacus tab to appear in Office applications, unless directed below. This will not solve your problem, and may create other issues. VSTO Add-in The Macabacus tab disappeared or is not visible If the Macabacus tab is missing from the ribbon in one or more Office applications, then it is probable that the Macabacus VSTO add-in failed to load. Complete following steps to resolve this problem. If a step resolves this problem, completion of subsequent steps is unnecessary. Substitute 'PowerPoint' or 'Word' for 'Excel' as applicable. Important This is the most common support inquiry we receive.

The steps below will resolve this issue in all known scenarios when performed correctly. Please do not submit a support request without all information requested in the final step. • Check the Excel's dialog and check the Macabacus 20XX box if unchecked. If you do not see Macabacus listed here, skip to step #4.

• Check the Excel's dialog and re-enable Macabacus if disabled. Repeat step #1 if necessary.

• Check Task Manager (Details tab in Windows 8 and newer) to confirm that only a of the Excel is running. If multiple instances are running, quit them all and restart Excel. • Confirm that you followed the, including signing out of Windows if necessary and verifying that prerequisites are installed. • Confirm that Macabacus is installed in Windows' Programs and Features dialog. If so, repair the Macabacus installation.

If not, then follow the troubleshooting steps in the next section. • Open Registry Editor and navigate to HKEY_CURRENT_USER Software Microsoft Office Excel Addins Macabacus20XX.

If the LoadBehavior value is 0, change it to 3. To open Registry Editor, type regedit in Windows' Run prompt ( Win+R shortcut). • Confirm that the full desktop edition of Office is installed locally by checking for the presence of the InstallRoot registry key pictured below. If this key is missing, you must install Office locally. See Macabacus' for more information.

• In Windows Explorer, navigate to the folder C: Program Files (x86) Macabacus Macabacus 20XX, or its equivalent on your PC. Double click the file named Macabacus.Excel.vsto. If a resulting error message reads something like 'Unable to install this application because an application with the same identity is already installed.' , navigate to the folder C: Users%USER NAME% AppData Local Apps 2.0 and delete all files and sub-folders related to Macabacus there. Then, uninstall and reinstall Macabacus. If a resulting error message reads 'The following Microsoft Office solution cannot be installed due to a general installer error.' With error code 0x8007007E, then confirm that you have installed the VSTO Runtime prerequisite per step #4 above.

• If applicable, ask your IT staff to confirm that the steps above did not resolve your problem. • If you are still experiencing difficulty, and include screen shots of: • the COM Add-Ins dialog from step #1 with Macabacus 20XX selected, • the Disabled Items dialog from step #2, • the Task Manager from step #3 showing a single instance of Excel, • the Programs and Features dialog from step #5 showing Macabacus and the VSTO Runtime prerequisite, and • the Registry Editor dialog from step #7 showing the InstallRoot key. Additionally, include the outcome of each step above not addressed through the aforementioned screen shots.

The installer says that it requires Office 2016, which is already installed Confirm that you have the full desktop edition of Office installed locally by checking for the presence of the InstallRoot registry key pictured below. See our for more information. Macabacus will not install, or does not install properly If Macabacus failed to install properly in Windows, perform the following troubleshooting steps: • Ensure that you have the necessary Windows Administrator privileges to perform the installation. • Confirm that you followed the. • Check your list of installed programs under the Windows Control Panel to confirm that Macabacus appears in the list.

If Macabacus does appear, then confirm whether Macabacus has installed properly, but has simply failed to load in your Office application(s), by opening Excel and navigating to File > Options > Add-Ins. In this dialog, select COM Add-Ins from the dropdown menu and click Go. If Macabacus appears in the list of COM add-ins shown here (but is presumably unchecked), then your problem is more likely that Macabacus failed to load.