Sorry that you are seeing this issue. I ran few tests with renaming the files and could not replicate the problem at my end.
I am assuming you are on the latest Angular IDE i.e 2020.7.22.
Can you please give us some more details?
1. Is the freeze happening only when trying to rename a specific file type in a specific project or any file type in the workspace?
2. Do you see the freeze in a new workspace with a simple project as well?
3. Please share the .log file located at workspace dir/.metadata/.log along with the OS and version details. Rename the extension to .txt and attach it here.
4. If possible, please also send us 3-4 thread dumps when the IDE freezes. It would help us figure out what process is running. To take a thread dump, you will need to run jstack -l 9000 > dump1.txt
Please replace 9000 with the PID of the Angular IDE process, the jstack program can be found in the bin directory of any JDK installation. You can generate 3-4 dumps (sent to different files, of course) during the period of freeze, and attach those files here.