Corrupt ArcGIS Desktop .style file

Description

The ArcGIS Desktop .style file format, which stores symbols for rendering data, and can also be imported into ArcGIS Pro, can be corrupted.  Symptoms can inculde:

• When trying to symbolize data in ArcMap with symbols from the .style file, the .style  file may either not be visible at all, or specific symbols may be missing.
• When trying to import a .style file into ArcGIS Pro, the following error message may be returned:

"The following file did not convert."

Cause

The .style files may be corrupted by concurrent access by users, by virus-scanning software accessing the file while a user has it open, or other unknown processes.

Solution or Workaround

The .style file is actually a Microsoft Access database file. 

1. Open Microsoft Access, select File > Open and set the dialog to All Files.
2. Select the .style file and open in Access. 
3. If the file is corrupt in some way, the application saves a backup copy of the original file, and writes out a repaired copy of the .style file.