After rolling back to previous version of Directory (e.g. 14.1.02 to 12.0.18) on Linux, you may experience problems with DSA instances not starting up successfully.
Startup phase results in to failure with message stating your DSA is inconsistent.
Release : 14.1
Environment profile related.
Problem could be related to your Directory installation owner's/user's profile. As the .dxprofile might have been changed during an upgrade and now rolling back will have the old .dxprofile file in place, you may see this issue as you might be working in the same PUTTY windows. Exit out of that shell and re-launce it with 'su - dsa' command (here 'dsa' is assumed to be your Directory installation owner, which is most common).
Once you become 'dsa' user again (with 'su - dsa') , your DSAs should start successfully.