If the market watch is only freezing intermittently and they can make changes, can you please suggest they try the following steps:
- Remove any unnecessary indicators
- Close any charts that are not in use or not needed
- Close/refresh the market watch window and select "show all"
These steps should resolve the issue, but if they do not - then it may be a resource issue on the machine they are using (if there's any) , so they should also check for other programs that might be consuming resources.