IIS8 with php mysql 5.5 ERROR500 HELP me!

I use a win2012 server with matomo 。 IIS8 with PHP7.2 MySQL5.5 。one website is working well。
First time install:download matomo from matomo.org,unzip the package in C:/www/piwik …IIS make a new website ,choose C:/www/piwik ,default AppPoll ,connect as Administrator。
It just tell me that 500

you can see it at https://piwik.dabenni.com

please help me ,and tell me how to fix it!

In that case, check your error log and it will tell you what went wrong.

Error in Matomo: Matomo couldn’t write to some directories (running as user ‘iis apppool\defaultapppool’).Try to Execute the following commands on your server, to allow Write access on these directories:cacls C:\www\piwik\tmp /t /g iis apppool\defaultapppool:f If this doesn’t work, you can try to create the directories with your FTP software, and set the CHMOD to 0755 (or 0777 if 0755 is not enough). To do so with your FTP software, right click on the directories then click permissions.After applying the modifications, you can refresh the page.If you need more help, try Matomo.org.

I run that command and cmd tell me :