This article outlines the steps to fix KWizCom Calendar Plus web part Uninstall Error during a version upgrade. "The uninstall process cannot be complete because there are issues with msi files and appwiz.cpl file."
Product & Version
KWizCom Calendar Plus Standard Evaluation 4.x.xx for SharePoint 2007
KWizCom Calendar Plus Standard Evaluation 14.x.xx for SharePoint 2010
Resolution
It may have happened because old files were busy by some processes and the installer was not able to replace them. To resolve the issue, please follow these steps:
1. Create MSITEMP folder in C: drive
2. Create MSI folder inside MSITEMP
3. Copy the MSI file to C:\MSITEMP\MSI folder
4. Rename the file to setup.msi
5. Run CMD
6. Run the command: msiexec /a C:\MSITEMP\msi\setup.msi /qb TARGETDIR=C:\MSITEMP
7. Copy files Installer.dll and KWizCom.SharePoint.FieldControls.DualLookupType.Constants.dll to the folder where the product installed. The default one: " C:\Program Files\KWizCom\KWizCom SharePoint DualLookup Field"
8. Drag and Drop the KWizCom.Sharepoint.WebParts.CalendarPlus_Constants.dll file to GAC (C:\windows\assembly)
9. Try to uninstall it
10. After uninstalling please check that the files were removed from GAC.
11. Install the product again.