Can't see any form code or design

I moved my project from ver 7 to ver 8 (8.0.2.0). My project has three forms but I can’t see any code or design of any of them.

If I select any event who has code in the property event of some form, I can’t see code either.

If I make a change at project properties and try to save, change is not saved although I click ctlr-S. After that, I try to quit appstudio (File-Quit), it asks me if I want to Save, I say yes and It remains in appstudio, it doesn’t quit.

Here is the log:
2020-01-20 17:55:37,931 - root - ERROR - An exception has occurred!
Traceback (most recent call last):
File “MainFrame.py”, line 1040, in OnStart
File “IDEController.py”, line 64, in wrapper
File “IDEController.py”, line 2308, in OpenProject
File “IDEController.py”, line 408, in AddProject
File “IDEController.py”, line 64, in wrapper
File “IDEController.py”, line 1254, in Deploy
File “IDEController.py”, line 827, in WriteManifestJson
File “json_init_.py”, line 348, in loads
File “json\decoder.py”, line 337, in decode
File “json\decoder.py”, line 355, in raw_decode
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
2020-01-20 17:55:44,956 - root - ERROR - An exception has occurred!
Traceback (most recent call last):
File “ProjectManagerPanel.py”, line 666, in OnLeftDown
File “ProjectManagerPanel.py”, line 702, in OnTreeTreeSelChanged
File “IDEController.py”, line 2707, in select
File “WorkPanel.py”, line 505, in do_select
File “TabbedEditor.py”, line 175, in FormEditor
File “TabbedEditor.py”, line 76, in init
File “TabbedEditor.py”, line 60, in _init_ctrls
File “appstudio\editor\design.py”, line 454, in init
File “appstudio\editor\design.py”, line 1009, in _refresh_webview
AttributeError: ‘Project’ object has no attribute ‘_tempdir’
2020-01-20 17:55:45,181 - root - ERROR - An exception has occurred!
Traceback (most recent call last):
File “appstudio\editor\design.py”, line 861, in on_webview_load
File “appstudio\editor\design.py”, line 1009, in _refresh_webview
AttributeError: ‘Project’ object has no attribute ‘_tempdir’
2020-01-20 17:55:50,132 - root - ERROR - An exception has occurred!
Traceback (most recent call last):
File “ProjectManagerPanel.py”, line 808, in OnMenuViewCode
File “IDEController.py”, line 2707, in select
File “WorkPanel.py”, line 505, in do_select
File “TabbedEditor.py”, line 175, in FormEditor
File “TabbedEditor.py”, line 76, in init
File “TabbedEditor.py”, line 60, in _init_ctrls
File “appstudio\editor\design.py”, line 454, in init
File “appstudio\editor\design.py”, line 1009, in _refresh_webview
AttributeError: ‘Project’ object has no attribute ‘_tempdir’
2020-01-20 17:55:50,316 - root - ERROR - An exception has occurred!
Traceback (most recent call last):
File “appstudio\editor\design.py”, line 861, in on_webview_load
File “appstudio\editor\design.py”, line 1009, in _refresh_webview
AttributeError: ‘Project’ object has no attribute ‘_tempdir’

Thanks.
David.

Try running the project. Are there any messages in the Chrome Console?

It doesn’t start with F5 or [Run-Start in Desktop Browser]. Run icon below menu is disabled.

I haven’t seen that the status bar, at the bottom of Appstudio form, displays: “Creating index.html” (left side) and “Deploy Location: Desktop” (center). It has been in this way for one hour.

Could you zip your project folder and send it to me? I’d like to try this here.

Thanks for the project. When we opened it here, it was fine. Reopening again on your system worked too.

I have JUST THE SAME troubles here quoted:

The only doubt is that i made the project in a version earlier than 7.4 i’m trying to install, like 7.3 or 7.0.
Is it possible?

I’m sorry - I’m not sure what you are asking here.

right, bad english sorry, i ment:
I don’t know if the problem is that i developed the project with vers. 7.0 and I am using 7.4 instead

Projects in 7.0 will work fine in 7.4.