Troubleshooting PDF viewing problems in dtSearch Desktop/Network

Last Reviewed: May 19, 2013

Article: DTS0166

Applies to: dtSearch Desktop

PDF files appear normally but without hit highlighting

To make hit highlighting work in Adobe Reader or Adobe Acrobat DC, X or XI, you will need dtSearch version 7.71 or later, and you will also need a dtSearch plug-in for Adobe Reader or Adobe Acrobat.  To get the plug-in, install dtSearch version 7.71 or later, run dtSearch Desktop, and click Options > Preferences > PDF View Options > Configure Plug-in.  For information on this plug-in, please see

Alternatively, you can have dtSearch display PDF files as plain text (without using Adobe Reader).  To do this, run dtSearch Desktop and click Options > Preferences > PDF View Options, and check the option to "View PDF files as text".

If you have the plug-in installed and PDF highlighting still does not work, you may have Adobe Reader "Protected Mode" or "Protected View" enabled.  To change this setting, run Adobe Reader and click Edit > Preferences > Security (Enhanced).  When Protected Mode or Protected View are enabled, Adobe Reader blocks the plug-in.  There are two ways to fix the problem:
(1) Disable Protected Mode or Protected View in Adobe Reader, or
(2) Install Adobe Reader XI, and click the "Trust this host" banner that pops up the first time you open a retrieved PDF file.  This is preferable to disabling Protected Mode generally because it lets you preserve the security benefits of Protected Mode on untrusted sites.

PDF files always open in a separate window

(1) Check the setting in dtSearch Desktop:  In dtSearch Desktop, click Options > Preferences > External Viewers, and make sure the box to "View PDF files in a separate Adobe Reader window" is not checked.

(2) Configure Internet Explorer to allow Adobe Reader to display PDF files.  Please see this Adobe help page for more information:

To test your Internet Explorer configuration, open this link in Internet Explorer to see if the PDF file displays inside the browser window:

(3) If you have an older version of Adobe Reader or Adobe Acrobat (version X or earlier), click Edit > Preferences > Internet, and under "Web Browser Options" make sure the box to "Display PDF in browser" is checked.  Sometimes this option is checked but Adobe Reader seems to ignore it anyway.   If this happens, uncheck the box, click OK, then open Edit > Preferences > Internet again, re-check the box, and click OK.  

(4) If you are running the 64-bit version of dtSearch Desktop (dtSearch64.exe), try using the 32-bit version instead.  The 64-bit version cannot display PDF files in an embedded Adobe Reader window because there is no 64-bit version of Adobe Reader.

PDF files appear normally but without hit highlighting

dtSearch is able to highlight hits in PDF files if you have a compatible PDF viewer installed on your computer.  If the PDF viewer you use does not support hit highlighting, then PDF files will appear without hit highlighting in dtSearch.  For a list of compatible problems, please see PDF viewers that support highlighting hits.

Adobe Reader is installed but PDF files open using another product

Each PDF viewer that is installed can take over the role of viewing PDF files in a browser window, so if you installed or used another product since you installed Adobe Reader, that product may have taken over the role.  Usually doing a "Repair" on your Adobe Reader installation will fix this.  To repair your Adobe Reader installation, click Start > Control Panel > Programs and Features, click on Adobe Reader in the list of programs, and click "Repair".  Alternatively, if you have an older version of Adobe Reader, you can download and install the latest version of Adobe Reader from

PDF files appear as plain text instead of in Adobe Reader

(1) In dtSearch Desktop/Network, click Options > Preferences > External Viewers, and check that you have "Standard" selected under "PDF viewing options."

(2) The PDF file may have attachments.  To tell if a PDF file has attachments, open it in Adobe Reader and look for this icon on the right edge of the window: image4.gif.  Click the paperclip icon to see a list of any attachments in the file.

When dtSearch indexes a PDF file with attachments, the only way to highlight hits in the file is to extract the text because Adobe Reader has no built-in way to highlight hits in an attachment.  If you do not want to search in the attachments, click Options > Preferences > Indexing Options, and uncheck the box to "Index attachments in PDF files".  This will allow PDF files with attachments to be displayed normally after a search.  (You will need to rebuild your indexes after changing this option.)