OK I have taken a look at the upgrade.vb and I thnik my problem could be connected to the DataCache.ClearHostCache(True) call in the UpgradeDNN function.

I have downloaded the 4.9.3 source code, changed the notification message to "RJC VERSION - No Cache Clearing  Performing General Upgrades<br>" and commented out this function and recompiled the project. I then copied my DontNetNuke.dll to my DNN application.

However when I ran my upgrade the message still read as "Performing General Upgrades".

So have I copied the wrong dll?

Do I need to do anything else to implement my change?

Your thoughts & help would be greatly appreciated.

I must of copied the wrong DLL's - DoH!!!

Anyway I recompiled the DontNetNuke.dll with the DataCache.ClearHostCache(True) function commented out of the UpgradeApplication function and copied the DLL across to my portal and reran the 4.9.3 upgrade and it completed successfully.

So it would seem that my Portal has a critical error whenever the DataCache.ClearHostCache(True) function is called. I have tried upgrades, module installations and Portal deletes and I get fatal errors - some even requiring a full site restore!

Not too sure what I can do about this - I cannot remove many of the 200+ child portals as they are business critical. I have spoken to our implementation team who create these child portals as some of them are VERY big - one has over 700 pages! Again very little can be done about this in the short term.

So now I am thinking of amending the DotNetNuke.DLL so that the DataCache.ClearHostCache(True) and ClearModuleCache subroutines doesn't do anything, i.e. just adding an exit sub at the top of the subroutine.

Just how dangerous will this be?

can anyone advise?