Can't upgrade from BExec 15 1180 to FP1

Hello,

I have a Windows 2012R2 server with Bexec 15, named BEXEC, with a remote SQL Database on the server named SERVERSQL.

I'm unable to upgrade my BExec 15 v 1180 to FP1. I'm getting a security error :

"Can write to the file \\SERVERSQL\C$\Program Files\Microsoft SQL Server\MSSQL12.MSSQLSERVER\MSSQL\Binn\PTFEB6.tmp"

SERVERSQL is the remote server on which the Bexec's Database is running.

On the event viewer of SERVERSQL, I can find the security audit failure :

A network share object was accessed.
    
Subject:
    Security ID:        SOCIETY\BEXEC$
    Account Name:        BEXEC$
    Account Domain:        SOCIETY
    Logon ID:        0x323CD02F

Network Information:    
    Object Type:        File
    Source Address:        192.168.88.37
    Source Port:        52801
    
Share Information:
    Share Name:        \\*\C$
    Share Path:        \??\C:\

Access Request Information:
    Access Mask:        0x1
    Accesses:        ReadData (or ListDirectory)
                

What should I do ?

Thanks !