The language in the Chart Options dialog is in Chinese.
This issue will be resolved in version 10.03.00.78 of SewerGEMS. You can download version here: Downloading OpenFlows Software.
If you cannot upgrade, you can also edit the SewerGEMS.exe.config files found in the following two locations:
C:\Program Files (x86)\Bentley\SewerGEMS
C:\Program Files (x86)\Bentley\SewerGEMS/64
You can edit this in Notepad or Wordpad. Note that you will need administrative rights to edit this file and save it.
After opening the SewerGEMS.exe.config file in Notepad or Wordpad, find the highlighted entries below and delete them.
After saving these files, open the model. Chart Options will now be in English.
Change graph and profile appearance using Chart Options