Simon's Citricks

In Citrix XenApp 7.15 with Reciever 4.9 Citrix run into an error when users are running an informative calculation within SAP. The error message tells that Citrix HDX Engine stopped working and the user is getting kicked out of the session. When he is logging on again, informative calculation is finished without any problems. After a Citrix case and a lot of traces we got the information that SAP sends for some reasons 42 sound files in 16 seconds during the calculation and Citrix crashes with file no. 41. We disabled the sound settings in SAP GUI and the problem was solved. Excuse the german Screenshot: At the sound settings you can disable sound signal. The reg key you need for disabling in a policy is: HKEY_CURRENT_USER/Software/SAP/General/Appearance/Sound Choose Reg_SZ and set it to "off" Turn this off and you're fine.

Like everybody of us heard we have Spectre and Meltdown as new threads for our customer environments. Microsoft brought out an article where they describe the threads and vulnerabilities and some recommendations. https://support.microsoft.com/en-us/help/4073119/protect-against-speculative-execution-side-channel-vulnerabilities-in This is just a short documentation. If you want a more detailed documentation, see the Microsoft link. I just want to make you aware of a PowerShllscript which checks your installed patches and what you need to patch to clean the situation in your environment. https://aka.ms/SpeculationControlPS - Download the ZIP and extract everything to a folder.  - Go to the folder with the extracted PowerShell-Module  and run following command: $SaveExecutionPolicy = Get-ExecutionPolicy Set-ExecutionPolicy RemoteSigned -Scope Currentuser -Force Import-Module .\SpeculationControl.psd1 Get-SpeculationControlSettings Set-ExecutionPolicy $Sav

A customer had the issue that some servers randomly froze. It was always another server and there was no schema so we could say when it will happen. In the event viewer of the server you'll see a time lag for the log entries. In the screenshots below, you’ll see that single entries get an old date and afterwards it will jump back to the actual date. This happened at all the frozen Servers. The events itself are irrelevant. There are always new events independently from source and status. Additional the date was always 4.12 and time 8:41 Suggestion : the Server gets a wrong time and this caused the error Solution : after we checked the NTP settings we saw that the VMICTimeProvider is still activated. You need it that the guest synchronizes the time with the host. We disabled the provider so that the server only gets its time from the NTP. Afterwards we didn’t had the freezing problem anymore. 

Problem After we moved the customer environment from XA 6.15 to 7.15 we had the problem, that the users complained about their desktop. it was flickering every now and then. Sometimes after 2 MInutes sometimes after an hour. No special programm was runned which could have been causing the issue.  After a long troubleshooting session we came accross, that the flickering always occured during the GPO Upate running all 90 minutes in the background. We made a call with Microsoft and they responded it was by design https://msdn.microsoft.com/en-us/library/ms812018.aspx https://technet.microsoft.com/en-us/library/cc940895.aspx?f=255&MSPPError=-2147217396 "Consider notifying users that their policy is updated periodically so that they recognize the signs of a policy update. When Group Policy is updated, the Windows desktop is refreshed; it flickers briefly and closes open menus. Also, restrictions imposed by Group Policies, such as those that limit the programs use