Hi

I've spent the better part of a day trying to solve a problem I had when I was trying to update from 4.11.10 to 6.0.0.

I got stuck at 90%, and got one of the following errors when trying to run the Umbraco upgrade process (I'm just going to mention them all to make this post more searchable):

"The database configuration failed with the following message: 
'FK_umbracoAppTree_umbracoApp' is not a constraint. Could not drop constraint"

"The database configuration failed with the following message: 
'FK_umbracoUser2app_umbracoApp' is not a constraint. Could not drop constraint"

"The database configuration failed with the following message: 
'FK_umbracoUser2app_umbracoUser' is not a constraint. Could not drop constraint"

I had gone from 4.7.1 --> 4.7.2 --> 4.8.0 --> 4.9.0 --> 4.11.10 --> 6.0.0, as per the recommended upgrade path given by Lee Kelleher here: http://code.leekelleher.com/umbraco/archive/

Anyway, I found out that the constraints did sort of exist in my database -- they just had different/wrong names.

For example: Rather than 'FK_umbracoUser2app_umbracoApp', the constraint was called 'umbracoUser2app_FK_umbracoUser2app_umbracoApp'.

I figured it was safe to rename the constraint since the names were so similar. After I renamed the constraint one at a time (attempting to run the Umbraco upgrade process between each renaming), the upgrade process was finally successful.

I'm not sure whether I committed a no-no, but it seems to have worked for me :-) Hopefully this can save other people with the same problem some time and frustration.

SQL for finding constraints in the database:

SELECT * FROM sysobjects WHERE name like '%constraintname%'

SQL for renaming a constraint:

sp_rename 'umbracoUser2app_FK_umbracoUser2app_umbracoApp', 'FK_umbracoUser2app_umbracoApp'