when you have this error, the boinc processrun but no work are done. To solve the problem :

1) Stop the process boinc and boinc manager in the task manager
2) On the directory of boinc edit it's property
3) change ATTRIB Read only and APPLY for all directory project,, and subdirectory and files.
4) Restart BOINC,it will work again.

Bye.

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