Currently, LINQPad v5 and v7 both use the "Web Pages and Excel 2003 XML Spreadsheets" file type (format) when exporting data to Excel from the LINQPad Results pane. Under non-regulated conditions, it is possible to open Excel's Trust Center and authorize the "Web Pages and Excel 2003 XML Spreadsheets" file type (Trust Center -> File Block Settings). However... many companies must abide by security posturing in today's environment. As such, security policy auditors such as Tenable have identified that this file type format should be BLOCKED from opening in Excel (https://www.tenable.com/audits/items/CIS_Microsoft_Office_Excel_2016_v1.0.1.audit:29268ad4a1c7bb369b13db79d95af0ef). Unfortunately (or fortunately, however you look at it), many corporations are REQUIRED to implement standard policies such as this.

Needless to say, we are such a corporation and Excel is blocked from opening this file type. Because of this, when exporting to Excel from LINQPad, you may or may not get an Excel error/info box pop up telling you that the file type is blocked and how to manually edit Trust Center to allow. Often, the box does not appear and you are left wondering why LINQPad is "hung" and the only work around (if you can't click "OK" to clear the Excel info box) is to manually kill LINQPad using Task Manager (or, if you understand the issue, you can hunt for the process from Excel in Task Manager, kill it, and LINQPad will resume and in doing so, LINQPad pops up its own error reporting "crash" box identifying that a System.Reflection.TargetInvocationException has been thrown).

Would sure love to provide amplifying screenshots, but can't do that here in this "post your idea" feature.

Regardless... cybersecurity threat vectors are constantly evolving and for security reasons, as holes or implications are found, they must be closed. If LINQPad continues to use communication vectors (i.e. with Excel) that are no longer viable from a security standpoint, we'll suffer loss of LINQPad functionality.

Respectfully request that LINQPad use a more modern file type (format) when exporting to Excel. Thank you.