Opening of old files in Calc

Formula disappears in cell for Migrated file from MS Office to Libare

Could you please inform on OS, MS Excel and LibO versions? How did you open the file?
Does the problem only occur for a certain file or for all files?
Did you make a test file in EXCEL and open it in LibO?

OS: MS Windows 7, MS Excel 2013, LibO: 4.1.2. Opened file by association (double click). Problem heppens in some of the files. No test file. This is a existing file which opens perfectly in Excel but not in LibO. Thanks for your response.