Make a complete backup of this 0.9.6.3 on the Server
Make a second backup and don´t touch this.
Install Wamp version WampServer2.0i.exe on your laptop.
The good thing with Wamp is that you can switch between php 4.X and 5.X and this way can quickly find out where it goes wrong on what php version.
Start with php 4.X on your Wamp Server on your laptop.
Install the first backup of your website on your laptop with wamp and try all php versions. From the php 4.X or 5.X where it (possibly) goes wrong you can debug your website. Then upgrade modx evo on your laptop.
Once debugged and diagnosed on your local wamp you can upgrade modx evo on the server. If you are lucky there is not much to debug.
http://netcologne.dl.sourceforge.net/project/wampserver/WampServer%202/WampServer%202.0/WampServer2.0i.exe (very stable version)
WampServer2.0i.exe already comes with a lot of php versions included.
Download the necessary php version packages you need from the php website and include them in the Wampserver on your laptop.
[ed. note: sitecms last edited this post 13 years, 8 months ago.]