Creating symlink at "F:\Backup\PC name\180518-1316\C\Users\All Users" to "" failed. Incorrect function. (errorcode=1)

I have urbackup installed on windows server 2016. “PC name” is a local windows 10 machine not being backed up over the internet.

The full file backup seems to index for a while then errors out with this error:
Creating symlink at “F:\Backup\PC name\180518-1316\C\Users\All Users” to “” failed. Incorrect function. (errorcode=1)

Info
18/05/18 13:29
Indexing of “C” done. 38139 filesystem lookups 0 db lookups and 0 db updates
Info
18/05/18 13:29
PC name: Loading file list…
Info
18/05/18 13:29
PC name: Started loading files…
Warnings
18/05/18 13:29
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\Certificates\fullchain.pem” to “F:\Backup\PC name\180518-1316\C\Applications\Certificates\fullchain.pem”
Warnings
18/05/18 13:29
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\Lidarr\CookComputing.XmlRpcV2.dll” to “F:\Backup\PC name\180518-1316\C\Applications\Lidarr\CookComputing.XmlRpcV2.dll”
Warnings
18/05/18 13:29
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\Lidarr\Lidarr.Update\CurlSharp.dll” to “F:\Backup\PC name\180518-1316\C\Applications\Lidarr\CurlSharp.dll”
Warnings
18/05/18 13:29
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\Lidarr\Lidarr.Update\CurlSharp.pdb” to “F:\Backup\PC name\180518-1316\C\Applications\Lidarr\CurlSharp.pdb”
Warnings
18/05/18 13:29
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\Lidarr\FluentMigrator.Runner.dll” to “F:\Backup\PC name\180518-1316\C\Applications\Lidarr\FluentMigrator.Runner.dll”
Warnings
18/05/18 13:29
HT: More hardlink errors. Skipping…
Warnings
18/05/18 13:32
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\OmbiV3\Ombi.zip” to “F:\Backup\PC name\180518-1316\C\Applications\OmbiV3\Ombi.zip”
Warnings
18/05/18 13:32
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\OmbiV3\TempUpdate\Polly.dll” to “F:\Backup\PC name\180518-1316\C\Applications\OmbiV3\Polly.dll”
Warnings
18/05/18 13:32
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\OmbiV3\TempUpdate\Remotion.Linq.dll” to “F:\Backup\PC name\180518-1316\C\Applications\OmbiV3\Remotion.Linq.dll”
Warnings
18/05/18 13:32
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\OmbiV3\TempUpdate\SOS.NETCore.dll” to “F:\Backup\PC name\180518-1316\C\Applications\OmbiV3\SOS.NETCore.dll”
Warnings
18/05/18 13:32
HT: Error creating hardlink from “F:\Backup\PC name\180518-1138\C\Applications\OmbiV3\TempUpdate\SQLitePCLRaw.batteries_e_sqlite3.dll” to “F:\Backup\PC name\180518-1316\C\Applications\OmbiV3\SQLitePCLRaw.batteries_e_sqlite3.dll”
Warnings
18/05/18 13:32
HT: More hardlink errors. Skipping…
Errors
18/05/18 13:52
Creating symlink at “F:\Backup\PC name\180518-1316\C\Users\All Users” to “” failed. Incorrect function. (errorcode=1)
Info
18/05/18 13:52
Waiting for file transfers…
Info
18/05/18 13:52
Waiting for file hashing and copying threads…
Info
18/05/18 13:56
Writing new file list…
Info
18/05/18 13:56
All metadata was present
Info
18/05/18 13:56
Transferred 1.04274 GB - Average speed: 6.45366 MBit/s
Info
18/05/18 13:56
Time taken for backing up client PC name: 40m 21s
Errors
18/05/18 13:56
Backup failed