After Effects 17.7 Legacy UI Issue

Mar 18, 2021 by aescripts + aeplugins

There is an unfortunate bug in the After Effects 17.7 version which affects all panels that are using the "Legacy UI" feature which causes them to crash on startup.

Unfortunately, this is a bug that only Adobe can fix but thankfully there is a workaround:

1. The easiest fix is to reset your After Effects preferences

2. Use this nifty script created by Zack Lovatt (note that if AE is crashing at startup your only choice is to reset the prefs):  Toggle Legacy UI (for all scripts).jsx

3. Note that this is NOT recommended unless you have experience editing the prefs file. It's safest to just reset the prefs :-)

You can also fix it manually by updating your prefs with the following steps.

  1. Open the After Effects General Preferences
  2. Click the 'Reveal Preferences in Finder' button at the bottom
  3. CLOSE After Effect
  4. Open the Adobe After Effects 17.7 Prefs-indep-general.txt file in a plain text editor (this is very important to not mess up the encoding of the text file)
  5. Search for  “Pref_SUI_PANEL_USES_LEGACY_SKIN
    If you can't find this pref, make sure you are opening the right file, as AE will highlight the Prefs.txt file which is not the right file.
  6. Delete the entire block-- that is, the title heading and all of the script names below it.
  7. Save prefs file
  8. Relaunch After Effects 
  9. Relaunch panel