Crash when reloading page

Sometimes, there is a crash, when the page is reloaded while connected to a workspace and an extension is opened. The console lists two warnings/errors:

[09:30:00.339] WARNING - vispa.extensions - cannot create instance for empty extension (extensions.js:239:9)

TypeError: instance.applyFragment is not a function
http://localhost:4282/static/js/workspaces.js
Line 1303

After this, the opened extension is not available.
Can’t be reproduced in Safari, only Firefox (both on OSX)

(from redmine: issue id 2194, created on 2015-04-15 by fabian.heidemann, closed on 2015-04-15)

• Changesets:
  • Revision 2091 by Benjamin Fischer on 2015-04-15T08:28:12Z:

Wait with restoring of the session (from state or fragment) until all extensions are fully loaded. Should fix #2194

• Revision 2091 by Benjamin Fischer on 2015-04-15T08:28:12Z:

Wait with restoring of the session (from state or fragment) until all extensions are fully loaded. Should fix #2194