JEB 4.1.0 wasm decompilation issue

Skip to first unread message

Jun 27, 2021, 5:32:49 AM6/27/21
to JEB Decompiler
Hi, I"m observing on some functions inside .wasm (WebAssembly) decompilation error

void __f2912() {
    // Decompilation error

In console window I see the following:

Error: Instruction cannot be converted: 50133FFEh: 0B: 0 end                              [0,0]
This address points right to the end of the function

I'm using this SW:
JEB (jeb-demo)

Quesiton: are there any means (eg Decompiler options fine-tuning) to  mitigate this kind of error?

PS. I"ve seen similar issues on other functions, same reason I believe...

Jul 2, 2021, 6:20:31 AM7/2/21
to JEB Decompiler
I see same issue on version JEB

Jul 3, 2021, 3:48:20 AM7/3/21
to JEB Decompiler
Maybe this info will help to track down the issue?...
.code:50133FF3                 loc_50133FF3:    
.code:50133FF3    20 02                         0 [0]  local.get $L2                     
.code:50133FF5    10 80 01                      0 [1]  call __f1128
.code:50133FF8    1A                            0 [1]  drop
.code:50133FF9    20 01                         0 [0]  local.get $L1
.code:50133FFB    10 1D                         0 [1]  call Dr
.code:50133FFD    00                            0 [0]  unreachable
.code:50133FFE    0B                            0 [0]  end
.code:50133FFE                 __f2912          endp

maybe that "unreachable" causes JEB to malfuction

Also this stack might understand what is going on:

Error: Instruction cannot be converted: 50133FFEh: 0B: 0 end                              [0,0]
java.lang.RuntimeException: FAIL - unexpected condition
at com.pnfsoftware.jeb.core.units.code.asm.decompiler.AbstractConverter.convert(SourceFile:408)
at com.pnfsoftware.jebglobal.SM.Yz(SourceFile:56)
at com.pnfsoftware.jebglobal.Yz.Yg(SourceFile:115)
at com.pnfsoftware.jebglobal.Dz.Yg(SourceFile:134)
at com.pnfsoftware.jebglobal.Dz.Yg(SourceFile:121)
at com.pnfsoftware.jebglobal.Iq.Yg(SourceFile:545)
at com.pnfsoftware.jebglobal.Iq.Yg(SourceFile:344)
at com.pnfsoftware.jebglobal.rF.Yg(SourceFile:1127)
at com.pnfsoftware.jebglobal.rF.Yg(SourceFile:539)
at com.pnfsoftware.jebglobal.rF.Yg(SourceFile:512)
at com.pnfsoftware.jebglobal.rF.decompileToUnit(SourceFile:464)
at com.pnfsoftware.jebglobal.rF.decompileToUnit(SourceFile:128)
at com.pnfsoftware.jeb.rcpclient.handlers.HandlerUtil$
at com.pnfsoftware.jeb.rcpclient.handlers.HandlerUtil$

Nicolas Falliere

Jul 3, 2021, 3:57:16 AM7/3/21
to, JEB Decompiler
Thank you, will look into it. Do you have a sample file to share by any chance?

You received this message because you are subscribed to the Google Groups "JEB Decompiler" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To view this discussion on the web visit
Reply all
Reply to author
0 new messages