Recently I got quite a number of calculation errors on Rosetta. Is this a inherent problem of the algoritm? Also how can I move to another language?

Most of those tasks have failed with ‘Out Of Memory’ errors. Are you using the machine for other memory-intensive tasks at the same time as Rosetta is trying to run? Rosetta tasks typically require several hundred megabytes of RAM.

When you say “move to another language”, do you mean you want to change the display language of the BOINC Manager? You can do that in Options » Other options » General.