Did you get anywhere with this as I have the exact same issue on the same kind of setup. Using the sample scripts and database (FMPHP_Sample.fmp12) sometimes gives the right kind of result and other times will just generate an error and stop working. So for example clicking the link for the "America 24/7 Example" sometimes returns the list of results and other times just brings back
Error: Unable to open file
America 24/7 Collection Title Publisher Qty Available
The only thing in the FileMaker logs that matches the datestamp for the error is127.0.0.1 127.0.0.1 - PHP 802 565 "/fmi/xml/fmresultset.xml?-db=FMPHP_Sample&-lay=Form View&-findall&-sortfield.1=Title&-sortorder.1=ascend". This means that the scripting of php/XML for database access is unusable as it isn't consistantly working. No changes are made to the server that would explain the failure to be able to open the file.I can't find anything in the Event Viewer on the server that matches the datetime of the issues or mentions anything like it.Does this sound familiar to anyone else?Cameron,xxx.