Sage 50c US - Unable to View invoices

Hi,

I'm in the IT dept, and our accountants are reporting that they are no longer able to open invoices when they view the invoice of any kind the screen flashes for a second and then closes as if they didn't click it at all, no popup no warning.

 We have reinstalled sage 50 on the server and on the client computers, we have ran all the integrity checks and no problems reported. Nothing in the event viewer

The only thing I can find is the ErrorLog.txt on the server company directory, there appears to be one of these messages for every-time an invoice attempted to be opened.

Server 2012R2 

Sage 50 Quantum Accounting 2021

Build: 28.0.00.0.117

Installed Tax Service: 20200702

2020/10/23 09:17:39, N/A, CollectDataWebService PublicKeyWebService.SubmitRequest: System.NullReferenceException: Object reference not set to an instance of an object. at Sage.Peachtree.CollectData.PublicKeyWebService.DoWebRequest(Object param) at Sage.Peachtree.CollectData.PublicKeyWebService.SubmitRequest(Object param)
2020/10/23 09:17:39, N/A, CollectDataWebService PublicKeyWebService.DoWebRequest Communication Error: System.ServiceModel.CommunicationException: Security negotiation failed because the remote party did not send back a reply in a timely manner. This may be because the underlying transport connection was aborted. Server stack trace: at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.DoOperation(SecuritySessionOperation operation, EndpointAddress target, Uri via, SecurityToken currentToken, TimeSpan timeout) at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.GetTokenCore(TimeSpan timeout) at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout) at System.ServiceModel.Security.SecuritySessionClientSettings`1.ClientSecuritySessionChannel.OnOpen(TimeSpan timeout) at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout) at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation) at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at Sage.Peachtree.CollectData.IS50CollectDataService.S50GetPublicKey() at Sage.Peachtree.CollectData.PublicKeyWebService.DoWebRequest(Object param)

We have two companies we use on the same server, one of which has no problem but the other seems to be effecting everyone just with view the invoices, if you want to print the invoice directly from the form module it works just fine. 

Been on hold for about 2 hours with tech support and haven't talked to anyone, so here I am trying. Any suggestions?