# Javascript runtime error - Unable to reverse engineer **URL:** \ **Category:** Toad Data Modeler\ **Created:** [November 12, 2024, 9:14pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177 "2024-11-12T21:14:06Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![rmanivannan](https://avatars.discourse-cdn.com/v4/letter/r/a4c791/32.png) [@rmanivannan](https://forums.toadworld.com/u/rmanivannan)\ **Post date:** [November 12, 2024, 9:14pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/1 "2024-11-12T21:14:07Z")
Hi All, I'm using TDM 7.3, I was able to reverse engineer existing tables earlier. However today if I click reverse engineering-connections, I'm getting below error message. Could you please help me to fix this. Database platform: MySQL 5.7 ![image](https://global.discourse-cdn.com/quest/original/3X/a/0/a0e541e9014f36761a40240f1547533085c8a76f.png) Thanks ! Regards, Rajesh ---
**Author:** ![mem731](https://avatars.discourse-cdn.com/v4/letter/m/dfb087/32.png) [@mem731](https://forums.toadworld.com/u/mem731)\ **Post date:** [December 2, 2024, 5:53pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/2 "2024-12-02T17:53:45Z")
I am having the same issue with a connection to SQL Server. I was able to run a RE with the trail license TOAD Data modeler 7.2 but now with 7.3 and a software license in place, I get an error: ![toad dm re error](https://global.discourse-cdn.com/quest/original/3X/f/b/fb0793bde76163a87869c55cdf93aff4915d926f.png) ---
**Author:** ![rmanivannan](https://avatars.discourse-cdn.com/v4/letter/r/a4c791/32.png) [@rmanivannan](https://forums.toadworld.com/u/rmanivannan)\ **Post date:** [December 2, 2024, 6:10pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/3 "2024-12-02T18:10:44Z")
Quest support team said that TDM 7.3 will works fine until Windows 11 22H2. Please check your windows version by using command **winver** in command prompt. If yours is 24H2 we will see this "javascript runtime" error. Thanks ! Rajesh ---
**Author:** ![robert\_1444](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robert\_1444](https://forums.toadworld.com/u/robert_1444)\ **Post date:** [December 8, 2024, 8:31am UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/4 "2024-12-08T08:31:45Z")
Really? I'm sorry, but I'm starting to hate this software - TDM owner changed several times and support is ... no comment... what am I paying for? 14 days ago everything was fine, this week windows patched to 24H2 and TDM has problem after that... and it is not about reverse engineering only: I have this error when I want to open some other saved model! ---
**Author:** ![rmanivannan](https://avatars.discourse-cdn.com/v4/letter/r/a4c791/32.png) [@rmanivannan](https://forums.toadworld.com/u/rmanivannan)\ **Post date:** [December 9, 2024, 2:16pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/5 "2024-12-09T14:16:53Z")
That's true, I faced all the problem that you described above. Also, we will not be able to generate DDL, HTML report if TDM is on 24H2. I ended up having separate machine which is not on 24H2 to use TDM. Regards, Rajesh ---
**Author:** ![Gita.Sharifi](https://sea1.discourse-cdn.com/quest/user_avatar/forums.toadworld.com/gita.sharifi/32/16973_2.png) [@Gita.Sharifi](https://forums.toadworld.com/u/Gita.Sharifi)\ **Post date:** [December 9, 2024, 5:30pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/6 "2024-12-09T17:30:21Z")
Hi all, the issue is caused by the latest Windows 11 24H2 patch. Microsoft has made changes in JScript libraries by default, causing applications to use the JScript9Legacy.dll instead of JScript.dll. As a result, Toad is throwing errors while executing code which is written in the JScript language. We've documented the workaround in [KB article 4377885](https://support.quest.com/kb/4377885/) I'm posting the workaround here as well: As a workaround, apply the following steps: 1. Download the attached “TDM\_24H2\_fix.txt” 2. Rename the file extension from .txt to .bat: “TDM\_24H2\_fix.bat” 3. Right Click on the file and select “Run as administrator” What does this script do? It will add registry entry as: HKEY\_LOCAL\_MACHINE\Software\Policies\Microsoft\Internet Explorer\Main and changing JScriptReplacement to 0. For additional assistance please reach out to our Support team. [TDM\_24H2\_fix.txt](https://forums.toadworld.com/uploads/short-url/mxHVDTueJ0kEybzJLxOgY5ASpZd.txt) (124 Bytes) ---
**Author:** ![robert\_1444](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robert\_1444](https://forums.toadworld.com/u/robert_1444)\ **Post date:** [December 10, 2024, 8:01pm UTC](https://forums.toadworld.com/t/javascript-runtime-error-unable-to-reverse-engineer/60177/7 "2024-12-10T20:01:22Z")
I need to thank TDM/Quest servicedesk and developers - I was very angry when I detect this problem, but... they resolved my problem with little workaround and TDM is againf fully functional at this moment...