What is it that breaks CreateUUID in Mathematica 10.4.1 and how can I fix it?

All of a sudden my Mathematica 10.4.1 installation which worked well for several years does behave very strange. For example when I evaluate:

CreateUUID[]

this either returns unevaluated or creates a bunch of error messages about cloud connections. My suspection is that this is related with the paclet CloudObject-12.1.28. If I delete that it will be recreated and depending on whether I do a PacletManager`RebuildPacletData after that I either see error messages about some Cloud functionality or CreateUUID returns unevaluated. This started on three independent computers last night, so I suspect that it is not a broken installation but somehow related to changes in the WRI server setup. There seem to be other functions which create similar problems and cause some of my automated scripts to fail, but so far I haven’t been able to locate which functions these are.

My question is: Does anyone see similar problems or has an idea how I can fix this?

Here are the error messages for reference:

SetDelayed::wrsym: Symbol CloudObject`Internal`$ActiveCloudConnection is Protected. >>

Set::wrsym: Symbol $WolframCloudBase is Protected. >>

Attributes::locked: Symbol $WolframCloudBase is locked. >>

SetDelayed::write: Tag CloudObjectInformationData in MakeBoxes[BoxForm`a_CloudObjectInformationData,BoxForm`fmt_] is Protected. >>

TagSetDelayed::write: Tag PermissionsGroup in DeleteObject[grp_PermissionsGroup] is Protected. >>

TagSetDelayed::write: Tag PermissionsKey in DeleteObject[key_PermissionsKey] is Protected. >>

 CloudFunction::nonopt: Options expected (instead of opts:OptionsPattern[]) beyond position 2 in CloudFunction[fn:Except[_Failure],head_:(##1&),opts:OptionsPattern[]]. An option must be a rule or a list of rules. >>

  Quiet[Block[{$ContextPath}, Needs["CloudObject`"]]];