Check for Adobe Reader for IE11

If you use WebViewer in FileMaker or HTMLViewer in Xojo on Windows with IE11 engine and you show PDF documents, you need a PDF plugin for IE. To check whether you have Adobe PDF Reader browser support installed for IE11, please start Internet Explorer (not Edge!), then go to the menu (gear icon in the toolbar on the right) and to the Manage Add-ons dialog:

Select toolbars and extensions first on the left, then go down to pick all add-ons in the popup menu. Then on the right, you should see Adobe PDF Reader in the list. This should show 32-bit and 64-bit versions there. If one is missing, repair your Adobe Reader installation. Seems like one version of Adobe Reader shipped this year where the 64-bit part was missing. You may get current one where it is included again.

PS: See also Windows updates breaks PDF display in FileMaker