Error message "The file format and extension of 'JetReports.xll' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?" is received when opening Microsoft Excel and in turn the Jet Reports Excel Add-in.
If you click yes, a message is displayed in Microsoft Excel which says "This program cannot be run in DOS mode." along with randomized text:
Cause:When the Jet Reports installer is run, it will try to detect whether the installed Microsoft Office package is 32bit or 64bit. Sometimes it is unable to find the correct platform and as such will install the wrong one. This results in the above error.
2. In Microsoft Excel, navigate to File --> Account --> About Excel and make note of whether the installation is 32bit of 64bit:
3. Download the Jet Reports MSI installer from here and extract the files to an appropriate location.
4. Open command prompt as administrator and run the following command:
5. Once the installation is complete, open Microsoft Excel and retest for the issue. If you had previously disabled the Jet Excel Add-In then you need to re-enable it using the 'Enable Jet Add-In' applet in the Windows Start Menu before opening Microsoft Excel.
If you intend on installing other Jet Reports components on the same machine, install the Jet Excel Add-In using the above method and the other components using the consolidated installer.
There are additional commands that can be used with the command line installation of the Jet Excel Add-In. For more information see Command-Line Installation of the Jet Excel add-in using MSI