I found some (or many?) programs (ex. mspaint.exe, cmd.exe, conhost.exe, notepad.exe) never launch by XRun/XrunAndWait while some (ex. calc.exe) always launch successfully without problem. The same symptoms are observed for both Chrome and Firefox. For example, when I have a single-line macro
| XRunAndWait | C:\Windows\System32\mspaint.exe | |,
it halts without showing any new window/dialog, and when I have another macro
| XRunAndWait | C:\Windows\System32\conhost.exe | |,
it quits by an error showing an alert that no such file is found (cmd.exe, which is launched by conhost.exe, shows the halting symptom on the other hand). Both programs launch without problem by direct double clicking the file in file managers and by calling from PowerSell/cmd.exe with the exactly same file paths.
My system configuration is with Version 5.7.5 for Chrome and 5.7.6 for Firefox both running on the same machine of Windows 10.
I would like to know what is happening behind XRun and XrunAndWait, and hope it would be fixed if it is a bug.