Issue

When using the Merge Changes Here option to merge two branches in Studio Pro, the following error occurs:

System.IO.IOException: The requested operation cannot be performed on a file with a user-mapped section open.

This error prevents the merge from continuing and forces an abort. This occurs even on small changes.

Environment

Studio Pro v11.12.2 and older

Cause

A race condition between Studio Pro and Git causes this issue. During a merge, Git locks the .mxunit file while comparing content. The operating system keeps this lock in place even after Git finishes and releases the file. When Studio Pro then tries to save changes to the same file, the operating system blocks the write because it still sees the file as locked and the error occurs.

Solution / Workaround

Upgrade Studio Pro to v11.12.3 or newer and perform the merge.

Internal information related

284765
CCR-592, SOLP-4121
C04JZDSNPLP/p1784108141578199

Additional information

Mendix documentation: Version Control Menu – Merge Changes Here

Git merge fails with error: The requested operation cannot be performed on a file with a user-mapped section open