What is the reason for the strange behavior of MODX REVO?

Question

MODX

I use Modx revo for the 4th day, and for the 2nd time I am facing such a problem.
The first time helped a complete reinstallation of Modx.
This time I don't want to do it all over again.
I am using modx-2.3.3-pl-sdk, windows 7 x64, apache.
I cleared the cache folder, didn't help.
I went from another browser, it did not help.
Please help me solve this problem.
Here is a link to the video, it's easier to show here.
youtube.be/PNn2u1UQ-Rw

Answer 1

After removing these addons:
- codeMirror
- getPage
- getResources
- phpThumbOf
everything worked.

Answer 2

1. Try with another browser.
2. Delete /core/cache/
For the future, in order not to reinstall, restore /setup/ and update the system.