the Resource tree vanishes with every nearly every manager action

what do I see:
Elements and files are ok. The problem is that the resource tree vanishes with every change within the manager. If I change the resource the tree vanishes, if I change to system settings vanishes.
I'll get back, choosing right click, sort options.

any ideas
greetings
Olaf

Had this issue in a shared hosting at goDaddy. Was occurring after update to 2.3.1. They determined that MODx was making too many requests and getting temporarily blocked. Not sure what they did, but they tweaked something on the server side to eliminate the issue. Site has been working fine since. Took a lot of pushing to get them to take it seriously. Not really sure what the true solution was because I was trying things on my end at the same time goDaddy was supposedly making a change on their end.

[ed. note: mmcgee last edited this post 11 years, 10 months ago.]

It's easy for a hosting provider to simply block any behavior that may be questionable. If a single page, like the MODX Manager, makes a lot of AJAX requests it can trigger anti-DDOS protection. The server doesn't know what these requests are, it just knows that more than x number of requests came from the same IP address within x span of time. The hosting provider will need to configure an exception, or completely disable the protection, for your domain. The same thing often happens with strict mod_security configurations.