Am 21.03.2016 um 19:19 schrieb Mariano Martinez Peck <marianopeck@gmail.com<mailto:marianopeck@gmail.com>>: HI Johannes, Could I see the source of the DmQuartalsplan>>#initialize: ? yes, of course: 'From Pharo4.0 of 18 March 2013 [Latest update: #40626] on 21 March 2016 at 6:19:38.568095 pm'! !DmQuartalsplan methodsFor: 'initialize-release' stamp: ' 15/1/14 15:24'! initialize: einQuartal self lehrveranstaltungen: (SortedCollection sortBlock: [:x :y | x modul modulNummer <= y modul modulNummer]). self quartal: einQuartal! ! Joh. I think I workaround may be to do a Fuel replacement to replace the sortedCollection with an OrderedCollection and then a post initialize method. But again, probably seeing if the closure of the sorted collection is clean or not may have different behaviors. Cheers, On Mon, Mar 21, 2016 at 3:09 PM, Johannes Brauer <brauer@nordakademie.de<mailto:brauer@nordakademie.de>> wrote: Hi, I am trying to port a pharo2 application to pharo4. Therefore I have to migrate some fuel files from version 1.9 to 1.9.4. I've done this using the script shown in the EnterprisePharo Book in my pharo2 image, no problem. But trying to load the migrated fuel file into my pharo4 image I get the error message shown above. The source code of the initialize methods is the same in both images, of course. But the byte codes differ: Pharo2: 37 <70> self 38 <42> pushLit: SortedCollection 39 <8F 02 00 08> closureNumCopied: 0 numArgs: 2 bytes 43 to 50 ⦠Pharo4: 37 <70> self 38 <40> pushLit: SortedCollection 39 <8F 02 00 08> closureNumCopied: 0 ⦠What can I do? Johannes -- Mariano http://marianopeck.wordpress.com<http://marianopeck.wordpress.com/>