File Migration Settings

Sandboxie Control > Sandbox Settings > File Migration:

Before a sandboxed program can make changes to a file that already exists in your computer, Sandboxie first must make a copy of this file in the sandbox. However, making copies of very large files would be a long operation. For this reason, Sandboxie will only make copies of files that are below a certain maximum size. Files larger than this size will be considered read-only inside the sandbox, and any attempt to modify them will result in message SBIE2102.

Use this settings page to set the maximum size threshold, and whether or not you wish to see message SBIE2102 issued when an attempt is made to modify files larger than that maximum size.

Related Sandboxie Ini settings: CopyLimitKb, CopyLimitSilent.