({{, (RefLink[MultilaunchWarning, paclet:ref/MultilaunchWarning])
is a global option that specifies whether a warning is given when you try to modify user preferences while running two copies of the Wolfram System simultaneously.}})

OpenersNotesSection(Spacer1)Details

The purpose of this warning is to make the user aware that there is only one user preferences file per user. If more than one copy of the Wolfram System is running, changes made to this file may be alternately overwritten by the different copies, resulting in lost user preferences. The warning is given only when the Wolfram System tries to write to the preferences file, for example, when you change the setting for a global option in the Option Inspector.

With the default setting (RefLink[MultilaunchWarning, paclet:ref/MultilaunchWarning])->(RefLink[False, paclet:ref/False]), no warning is given when the Wolfram System tries to write to the preferences file, even if the file is being used by another copy of the Wolfram System.

With the setting (RefLink[MultilaunchWarning, paclet:ref/MultilaunchWarning])->(RefLink[True, paclet:ref/True]), a warning is given when the Wolfram System tries to write to the preferences file, if the same file is in use by another copy of the Wolfram System.

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