Symptoms

Upon upgrading to 4.x, you see unmigrated macros in place of tasklists:

dynamictasklist: task list macros declared inside wiki-markup macros are not supported

Upon applying the workaround from CONFSERVER-26866 - Dynamic task list will not migrate content within unmigrated wiki markup macro, you now see blank tasklists:

Cause

Confluence 4 expects to see the tasks stored in the bodycontent table, but prior versions of Confluence store this data in the OS_PROPERTYENTRY table. Confluence doesn't convert this data unless the tasklist is edited in someway in 3.5.

Resolution

You have two options that depend on how many tasklists you have that still store their information in the OS_PROPERTYENTRY table:

1. If there aren't too many broken tasklists:
   
   1. Rollback your instance and then upgrade to 3.5 instead of 4.x.
   2. Add and remove a task in every tasklist and then upgrade. Doing so in 3.5 will bring the tasks from the OS_PROPERTYENTRY table into the bodycontent table.
2. If there are a lot of unconverted tasklists:
   
   1. Rollback your instance and then upgrade to 3.5 instead of 4.x (doing so will allow you to avoid the workaround from CONFSERVER-26866 - Dynamic task list will not migrate content within unmigrated wiki markup macro).
   2. Write a script that pulls the information from the OS_PROPERTYENTRY table and populates the bodycontent table for each tasklist.