Some Useful Fixes That I've Found Have Worked For Me

 For anyone other than myself and the domain admin account – Outlook on a Citrix delivery server would open with the message “Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client. “  This also prevented the users from e-mailing documents as attachments direct from Excel, Word etc  - Even the Citrix Admin account was affected. Googled this for hours, did all the basic stuff about checking program defaults etc, setting file associations, repairing Office – uninstalling office, re-install, numerous re-boots – also checked all the folder permissions and compared to another Citrix Delivery server (Which did not have the same issue) – went through all the services, checked the local user permissions, checked and compared the local GPO, checked all the AD setups, deleted the profile for a test user, rebooted the server, logged on again as the test user to create a new profile – same issue.  Tried some of the suggested registry tweaks – didn’t work, so repaired office and put the registry back to how it was.Just about lost the will to live and left the Citrix delivery server in maintenance mode to stop users logging onto it whilst I re-googled the issue with different search parameters -At about 1am in the morning, I came across this solution – which worked!!
“This worked for me after a lot of searching... (Office 365 Outlook 2016)Solution:

1. Open registry by typing regedit in run.

2. Search for the office productguid in HKEY_CLASSES_ROOT\Installer\Components\

3. Right Click the Sub Key that started with (for me) 'F1291BD604B8604......'

4. Select Permissions, Add 'Everyone' and give read only Access to that group.worked a treat.. :)”

The comments on the forum from a lot of people are the same as me:

1. How on earth did you find this little gem?
2. Thanks for saving us hours of misery with no solution from Microsoft in sight

Adding this to my memoirs!! 

 Having researched now to convert a VM in Xencentre to a Hyper V VM and gone through all the rigmarole of copying the Xencentre VM, exporting to a xva file, converting to VMDK etc etc, on creating the VM in Hyper V it would not boot.  I had religiously followed all the google guidance on making sure all the Xen Centre/Citrix drivers etc had been removed prior to conversion.  Tried unsuccessfully for around 2 days with the same result and then stumbled across this:

"Xen VM's will not boot after a conversion to anywhere, until you remove the disk filter driver links in the registry.  

There are two locations which need to be removed by delete the data inside "UpperFilters"Windows Registry Editor Version5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e97d-e325-11ce-bfc1-08002be10318}] "UpperFilters"=hex(7):00,00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e96a-e325-11ce-bfc1-08002be10318}] "UpperFilters"=hex(7):00,00

Do this prior to running the conversion (from a running VM) and you will find that they then boot afterwards.This avoids the need to rebuild in a new environment.

There are also a number of services which are configured to start at boot time under {HKLM\SYSTEM\CurrentControlSet\Services}\ all have Xen in the name, and have a dword value of 0-3, make these all 4 to disable them..."

Worked a treat!

 Buy a Wacom One Pen Tablet unit for around £50 and connect via USB, install software and away you go.  Enables you to annotate word/excel/powerpoint/outlook documents on the attached writing tablet.  Yet to try PDF's but looks like you need PDF software that allows you to edit the underlying PDF's.

Website link - https://www.wacom.com/en-us/products/pen-tablets/one-by-wacom

Had an instance of temp files being created in a network directory, the same size as the original excel files.  If the file was deleted, it immediately re-appears when the folder contents were refreshed.  The google advice centres on file permissions, folder permissions, taking control of the directory etc - although well versed in the ways of folder permissions - none of these worked and the tmp files kept re-appearing.  The solution in my case was quite simple - the user had crashed out of Citrix system leaving files open, even though they were not open on the users desktop.  A quick scoot through the open files (Computer management - Shared Folders - Open Files) showed that the file server still reckoned these files were open - closing the open files cured the issue!!  Another simple solution if you know what you are looking for.

Had been struggling with this one for weeks on a Citrix 7.6 environment - IRIS helpdesk of little use as, as far as they could see, the installation was correct and they did not support client Citrix environments.  I'd un-installed, re-booted and re-installed the client software, installed the e-mail assistant service and the Invu Office add-ins - rebooted and ran as a user.  Also, deleted the existing "Invu" folder in the users %Appdata% directory.  Issue every time was when the user tried to open the software, error message popped up "there are x instances of Excel (Or Winword, Outlook), detected - click ok to close the application and retry".  Trouble is, clicking on this option shut down all instances of Excel/Word/outlook on the Citrix server so other users got booted out of their programs mid stream.  Tried all the user folder permissions etc, running the install direct from the users desktop as an admin user - all to no avail.  As I type, the solution (which I will find out if it has worked in the fullness of time) is to run the program executable as the Administrator - whole load of installs popped up the background before the program opened up - but it appears to have cured the issue for 2 users I have tried this fix on - fingers crossed!!

If you are running commvault compliance archiver to a separate server and believe that you have oodles of disk space available - beware!!!  Was getting persistent backup failures due to a lack of disk space (60GB free out of 200GB) - believe it or not, you need 50% disk space free, so it was shutdown of the compliance server, a change to the Hyper V settings to increase the disk size, a re boot followed by diskmgmt.msc to allocate the extra space - worked fine but it does mean that I've lost another 80GB of Hyper V disk resources.

 For some unexplained reason a QNAP device we were using for our on site backups decided to pack up and went off-line.  The restart function from the admin panel got the drive working but it instantly recommended a file system check, which when started, just hung at around 28%.  This process was repeated over the next few days with the file system check commencing and then the drive going off-line - the consequence of this was that no backups could take place.  QNAP helpdesk recommended a file check run from a ssh session.

1.  If you can SSH to NAS command line, please check if the mounted volume is cachedev1 (/dev/mapper/cachedev1 mount on /share/CACHEDEV1_DATA )
2. Usually volume name for cachedev1 is DataVol1. 

3. If mounted volume is cachedev1, please try below commands to stop services and un-mount cachedev1.
# /etc/init.d/services.sh stop
# /etc/init.d/opentftp.sh stop
# /etc/init.d/Qthttpd.sh  stop
Try un-mount /dev/mapper/cachedev1.
# umount /dev/mapper/cachedev1 

4. Verify, make sure cachedev1 is NOT mounted.
# df
5. Run check file system.
# e2fsck_64 -fp -C 0 /dev/mapper/cachedev1
6.After check file system has completed, reboot.
# reboot  

I have to say that this took around 2 weeks to complete on a 28TB drive but it did clear the errors.  However, as we could not write any data whilst it was sorting itself out I did have to source an alternative backup solution - not an ideal solution.

 When a user gets the error unable to run another instance of the application.

The user will not show on in the Citrix AppCenter.

You can either run these commands or manually stop and restart the Citrix IMA service via services manager.

net stop imaservice 

dsmaint recreatelhc 

dsmaint recreaterade 

net start imaservice

This needs to be run on all Citrix delivery servers in the farm

 When installing an application on a terminal server it is necessary to change the server to install mode by running “change user /install” from a command prompt or by performing the install through “Add/Remove Programs.” After the installation you must run “change user /execute” to bring it out of install mode. 

This ensures that the .ini files for the installed application are stored in the Terminal Server system directory. These files are used as the master copies for the user-specific .ini files. Why is this important? When a user runs an application for the first time, the application looks in the home directory for its .ini files. If it does not find them in the home directory it will look in the Terminal Server system directory and copy them to the user’s home directory. If an application is installed while the server is not in install mode, the .ini files will be saved to the home directory. New users will therefore be unable to pull down the .ini files from the Terminal Server system directory, and the application will not run.