Similarly, when you select an error in the list, the respective paragraph will automatically be activated. Depending on the criterion, you can handle the displayed error in different ways. For some errors, you will have to correct the error yourself or select "Ignore" (Ctrl+Shift+I). You also have to "Ignore" errors that you do not correct. This is not so important in the standalone mode, since you are the one in charge. However, you will have to do this for the mandatory criteria in the Offline Client, as otherwise you will not be able to finish the task.
In my opinion, it would be best to expressly "Ignore" all errors that you do not correct in the Offline Client mode, i.e. not only the mandatory ones. In this way, your customer will notice that you have seen the error and dealt with it. For other criteria, you will also see the option "Apply" (Ctrl+Shift+Enter). I find this feature very convenient, as Across will automatically correct the particular error without you having to find and correct the error manually in the Target Editor.
The "Spelling" criterion gives you additional options: You can add the word to the dictionary by clicking "Add to Dictionary", filter it with "Similar", or apply a suggested word, in which case the error will be corrected automatically without you having to intervene.