I recently completed the Development on Creatio guided learning course. With my instructor's assistance, I set up a local Creatio instance—labeled Dev1_DEV—on my Windows server.
After switching my D1_DEV local development environment to use File System Development Mode instead of the default Creatio IDE mode, I encountered an issue where my Creatio instance failed to load the necessary JS files related to SectionModuleV2 for Classic UI sections (e.g., System Settings, Lookups). I reverted my Web.Config file changes to disable File System Development Mode, which resolved the issue.
For reference, I have attached screenshots of the error messages from my console when attempting to access Classic UI sections while File System Development Mode was enabled.
Could you help me understand why switching to File System Development Mode prevents access to the required JS files for Classic UI sections? Aside from modifying the Web.Config file, I did not make any other changes to the system.
Any guidance on resolving this would be greatly appreciated.
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Hello,
We recommend checking if all the steps from the article have been completed:
https://academy.creatio.com/docs/8.x/dev/development-on-creatio-platfor…
For example, ensure that these values are set:
<fileDesignMode enabled="true"/>
...
<add key="UseStaticFileContent" value="false"/>
All steps must be completed.
Hello Kalymbet,
Hope all is well.
Thank you for providing that link. I followed its steps listed on the page as follows:
Enabled file design mode
Disabled UseStaticFileContent
Compiled my instance (no errors)
Downloaded packages to file system successfully (no errors)
Gave IIS Usr full access to the Terrasoft.Configuration file
I still received the same error. It looks like it is not able to find the SectionModuleV2.js file. 
Hello,
We also recommend that the user under which the application pool is running should also have full access to the {rootAppFolder}\Terrasoft.WebApp folder
Serhii Parfentiev,
Thank you for the suggestion. I added Full control access to the IIS User for the Terrasoft.WebApp folder and I still received the same issue. For reference, I attached an image of the Terrasoft.WebApp security properties.
Hello,
Could you please verify under which user the Application Pool is running? If you have changed the user, please make sure to grant permissions for this user too.
If this doesn't help, additionally please try the following scenario:
1) Deploy the application.
2) Authorize and allow the inner part of the application to initialize (after login, wait for the application to finish loading).
3) Only after that, make changes in the Web.config file to enable development on the file system and follow further instructions.