I have upgraded to FreePbx 2.6. How can I go back to 2.5.2? The call center module of Elastix does not work yet with 2.6 so I need to go back to 2.5.2. Can I just reinstall 2.5.2?
Yes, but you will have to enter all your settings again if you did not do a backup before your upgraded.
There are a lot of changes in the database between 2.5.2 and 2.6.0.