As IDM introduced this feature I suggested to make it also possible to open the found files. Unfortunately it looks like I was the only user which wanted that until now. I hope more users are requesting this enhancement by email from IDM. The same problem exists when running a Find In Files with an empty search string to get just a list of files.
The problem is that normally after a file name there is either (line number): or /line number: appended to the name of a file. UltraEdit requires at least the : to interpret a line as a line with a file name.
You can run your search with option Results to Edit Window and right click on every file name and click on first menu item to open the file.
If the configuration setting Show status information in output window is not enabled (by default it is enabled), you could also run the following script I quickly have written to simply append a : at end of every line in the output window which enables you to open the files with a double click.
var sOutputContent = UltraEdit.clipboardContent;
var sNewOutput = sOutputContent.replace(/\r\n/g,":\r\n");
If the configuration setting Show status information in output window is enabled the execution of the script above results in overwriting the current output window content with the script status information on start of the script and therefore the script can't get anymore the output of the Find In Files command.
Best regards from Austria