An Internet Explorer 9 canvas bug can cause images to disappear when you click to zoom or rotate the image.

Note: For this reason and many others, Accusoft DOES NOT RECOMMEND any Internet Explorer older than Microsoft Edge.

The issue occurs because PrizmDoc® for Java AJAX is drawing faster than IE 9 can handle.

To correct this issue, we added a variable in vvDefines.js called ie9DrawDelay. It inserts a delay in milliseconds into the IE 9 drawing code which can help work around this bug.

Please add this entry to the vvDefines.js file:

ie9DrawDelay: 900,

The vvDefines.js file is located in \virtualviewer\js\vvDefines.js.

The default value is 100 (100 milliseconds). The user can set the ie9DrawDelay variable as high as necessary. However; if it is set too high, it could cause a delay for the user each time they zoom.

The ie9DrawDelay variable will not work if IE 9 is set to compatibility mode. It will only work in IE 9 standard mode. Please try adding

<meta http-equiv="X-UA-Compatible" content="IE=Edge">

to index.html to force IE 9 standard mode.