Thank you for your replys. Andy > I could then point my browser at the server on 9080 and get the introductory Andy > page. However, if I try to do anything else, like go to admin page or quick Andy > start documentation, the server raises the following debug message and the Andy > browser says that the document returned no data, try again later or contact Andy > system administrator : Andy > Stack overflow: pid 23282, proc python, addr 0x14085ffe8, pc 0x120038c18 Ethan> Which zope did you get? from source, I assume. If so, what python are you Ethan> running? It's Zope source version 2.1.6. Python version 1.5.2 configured with --with-dec-threads. Dieter> It seem that the thread stack is not large enough and that Dieter> Python (one of the Python threads) gets a stack overflow. Dieter> You may try to look into the OS documentation to find, whether Dieter> you can specify a default thread stack size. We uped the settings and rebooted, but to no avail. The current settings are: proc: maxusers = 512 max-proc-per-user = 512 max-threads-per-user = 1024 per-proc-stack-size = 33554432 max-per-proc-stack-size = 67108864 Dieter> If Python uses Posix threads on your machine, you may find the information Dieter> in the "pthread_create" documentation. Where abouts is this documentation kept ? Andy.