If you set Display Errors to OFF (and also may need to modify the Output Buffering) it will install. I have had this very same issue when installing our demo packages.
Reggie & Kat05,
I did as Reggie suggested and IT WORKED! Thank you both so much.
Kat05 had suggested doing that earlier but I didn't think it was relevant, given that I had previously (on an older version of xampp) installed many rocketlaunchers with display_errors=On (and output_buffering=On/4096) and had no problem.
I am left wondering why these settings could cause the installation to fail when they seem to have no direct relationship to the process. It seems totally irrational, but there must be a reason, e.g. too many errors being generated (?). Anyway, no answer necessary on that.
Thanks again,
Walt
We had some #_extension entries that needed to be removed and now our dev version of the Xenon RocketLauncher installs fine with Display Errors set to On (we will release dev version soon). Thanks for reporting the issue.