100% full access. I can access it from the server with the Windows Authentication account I am using

EDIT: I forgot to show the error message that I get when using the \\hostname\d$ share

The database is already fully recovered.

As soon as I switch it to local storage, it runs without any issues

Here's the full script

USE Master;

GO

SET NOCOUNT ON

-- 1 - Variable declaration

DECLARE @dbName sysname

DECLARE @backupPath NVARCHAR(500)

DECLARE @cmd NVARCHAR(500)

DECLARE @fileList TABLE (backupFile NVARCHAR(255))

DECLARE @lastFullBackup NVARCHAR(500)

DECLARE @lastDiffBackup NVARCHAR(500)

DECLARE @backupFile NVARCHAR(500)

-- 2 - Initialize variables

SET @dbName = 'database'

SET @backupPath = '\\hostname\d$\SQLBACKUP\database\'

-- 3 - get list of files

SET @cmd = 'DIR /b ' + @backupPath

INSERT INTO @fileList(backupFile)

EXEC master.sys.xp_cmdshell @cmd

-- 4 - Find latest full backup

SELECT @lastFullBackup = MAX(backupFile)

FROM @fileList

WHERE backupFile LIKE '%.BAK'

AND backupFile LIKE @dbName + '%'

SET @cmd = 'RESTORE DATABASE ' + @dbName + ' FROM DISK = '''

+ @backupPath + @lastFullBackup + ''' WITH NORECOVERY, REPLACE'

EXEC (@cmd)

-- 4 - Find latest diff backup

SELECT @lastDiffBackup = MAX(backupFile)

FROM @fileList

WHERE backupFile LIKE '%.DIF'

AND backupFile LIKE @dbName + '%'

AND backupFile > @lastFullBackup

-- check to make sure there is a diff backup

IF @lastDiffBackup IS NOT NULL

BEGIN

SET @cmd = 'RESTORE DATABASE ' + @dbName + ' FROM DISK = '''

+ @backupPath + @lastDiffBackup + ''' WITH NORECOVERY'

EXEC (@cmd)

SET @lastFullBackup = @lastDiffBackup

END

-- 5 - check for log backups

DECLARE backupFiles CURSOR FOR

SELECT backupFile

FROM @fileList

WHERE backupFile LIKE '%.TRN'

AND backupFile LIKE @dbName + '%'

AND backupFile > @lastFullBackup

OPEN backupFiles

-- Loop through all the files for the database

FETCH NEXT FROM backupFiles INTO @backupFile

WHILE @@FETCH_STATUS = 0

BEGIN

SET @cmd = 'RESTORE LOG ' + @dbName + ' FROM DISK = '''

+ @backupPath + @backupFile + ''' WITH NORECOVERY'

EXEC (@cmd)

FETCH NEXT FROM backupFiles INTO @backupFile

END

CLOSE backupFiles

DEALLOCATE backupFiles

-- 6 - put database in a useable state

SET @cmd = 'RESTORE DATABASE ' + @dbName + ' WITH RECOVERY'

EXEC (@cmd)