Can you provide more information on the URLs used (an example of a working URL and a non-working URL) and on the error received?

This URL will only yield 1 hit, so it then errors when it tries to load the document:

http://Servername/weblink8/search.aspx?dbid=0&searchcommand=%7B%5BGeneral%5D%3A%5BManifest%20Number%5D%3D%22012559144JJK%22%7D

If they take off the last 5 digits of the Manifest Number and replace it with an *, then the search returns a list of multiple documents:

http://Servername/weblink8/search.aspx?dbid=0&searchcommand=%7B%5BGeneral%5D%3A%5BManifest%20Number%5D%3D%220125591*%22%7D

Because the first search returns a single result, WebLink tries to load that document into the viewer and throws an error on the Page1.aspx.  With the 2nd search, it returns multiple results, so WebLink returns a search results listing, does not try to load any documents into a viewer and does not error.

This system is only used internally on their intranet and authenticated with Windows Authentication.  We have grated the Domain Users group full control on all Temp folders in the WebLink directory, but this has not helped our issues.

Here is in the IIS log file when we try to search from URL and only have 1 result:

2014-12-15 16:04:06 xxx.xxx.xxx.xxx GET /weblink8/search.aspx dbid=0&searchcommand=%7B%5BGeneral%5D%3A%5BManifest%20Number%5D%3D*012559144JJK*%7D 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) - 302 0 0 703
2014-12-15 16:04:06 xxx.xxx.xxx.xxx GET /weblink8/0/doc/64328/Page1.aspx - 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) - 302 0 0 0
2014-12-15 16:04:06 xxx.xxx.xxx.xxx GET /WebLink8/Error.aspx aspxerrorpath=/weblink8/0/doc/64328/Page1.aspx 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) - 200 0 0 203

And here is the IIS log from trying to export to PDF:

2014-12-15 15:55:49 xxx.xxx.xxx.xxx GET /WebLink8/GeneratePDF.aspx _=1418658949116&Key=WLOpenDocumentPages65378&PageRange=1+-+1 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) http://Server/weblink8/DocView.aspx?id=65378&searchid=a3bf433d-5d13-499d-aa7a-0ddc849abd37&dbid=0 200 0 0 437

2014-12-15 15:55:49 xxx.xxx.xxx.xxx GET /WebLink8/PDFTransition.aspx Key=WLPDFCreatorThread1 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) - 200 0 0 343

2014-12-15 15:55:52 xxx.xxx.xxx.xxx GET /WebLink8/PDFTransition.aspx Key=WLPDFCreatorThread1 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) http://Server/WebLink8/PDFTransition.aspx?Key=WLPDFCreatorThread1 200 0 0 218

2014-12-15 15:55:52 xxx.xxx.xxx.xxx GET /WebLink8/PDF/mh0bljvpio313ran1ffpjn55/1/2014-12-14+AETS+Data+Check.pdf - 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) http://Server/WebLink8/PDFTransition.aspx?Key=WLPDFCreatorThread1 302 0 0 218

2014-12-15 15:55:52 xxx.xxx.xxx.xxx GET /WebLink8/Error.aspx aspxerrorpath=/WebLink8/PDF/mh0bljvpio313ran1ffpjn55/1/2014-12-14%20AETS%20Data%20Check.pdf 80 Domain\MAJ2 xxx.xxx.xxx.xxx Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+MS-RTC+LM+8) http://Server/WebLink8/PDFTransition.aspx?Key=WLPDFCreatorThread1 200 0 0 234

any thoughts on what would cause these issues?

From how you've described the problem (URLS identical except for number of documents returned, occurring on export and print), the issue is not related to the searching. Is the single document that is returned image pages, or an electronic document (such as a PDF)? Is there anything logged to the event viewer? If there are no more detailed error messages, it might be a good idea to open a support case.

There is no other error information that I could find.  What does it take to turn on application tracing for WebLink 8.2.2?