SCCM stopped WSUS Sync

[scalyback]

All of a sudden our SCCM server on a disconnected network has decided to just not sync anymore, no idea why it has happened no changes have been made but from a bit of googling I found this in the wsyncmgr.log
Sync failed: The operation has timed out. Source: Microsoft.UpdateServices.Internal.DatabaseAccess.ApiRemotingCompressionProxy.GetWebResponse

In the Component Status for SMS_WSUS_SYNC_MANAGER:
WSUS Synchronization failed.
Message: UssInternalError: InvalidOperationException: .
Source: Microsoft.SystemsManagementServer.SoftwareUpdatesManagement.WsusSyncAction.WSyncAction.SyncWSUS.
The operating system reported error 2147500037: Unspecified error

It's quite annoying as this was working just fine in the middle of July but now nope July & August updates are either not downloading for July when I create my Software Update Group or as in August updates I run my monthly robocopy to put them on the SCCM Server, run the wsusimport and the next day sync the updates and that is where it is now all going wrong.

I have the feeling that I am going to have to remove the Software Update Point and the SCCM Instance on my db server, but do not want to do that today or Friday, unless anyone has any other ideas, I have done extensive research and it all leads to the removal and re-installation of the SUP. 
Any help would be gratefully received.

[#2]

Have you do server cleanup wizard?

[#3]

Couple of things you can check - Have a look at the resources on the SUP server. See if a cleanup is required or not.

[#4]

@Mathg76, @rahuljindal-MVP

Yes first thing I did was check the SUP was running as the others on the other networks so the cleanup after 3 months is still in place. Feel like I should not take any time off :)

[#5]

Others? Do you have more than 1 SUP? How are they synching?

[#6]

We have one SUP per network, all settings are the same just this one does not sync with itself, but has done for the past 2 years. I am on the thought that I will have to uninstall the SUP role and backup the sql db then recreate from scratch

[#7]

@scalyback 

Hi there,

Just remember something, i needed to remove products from the WSUS list because it stop my sync maybe you can check that....

The products are the visual studio all versions.

I remove them wait some time  and after my sync started.

[#8]

@Mathg76
Yes one of the first things I checked, we do not have it.
I am resigned to removing the SUP and instance, re-boot over night and re-install the next day.

[#9]

i think also that is the next step to do... good luck