You usually get these dumps in ST22 with the runtime error as CONVT_CODEPAGE and it says that the character set conversion is not possible. So, how to we get rid of these errors?

These errors are caused when you try to download the file with some special characters in the unicode system. When SAP system is not able to convert the special characters, it ends up with this system dump.

Just add the clause IGNORE CONVERSION ERRORS when you try to open the dataset and all these special characters which cannot be converted into a specific code page will be skipped. You can also add the clause REPLACEMENT CHARACTER space, with this addition, all the special non convertible characters will simply be replaced with space.