Seems WIX is not stable.
when you try to install the app again with the settings (apikey and secretkey) you already have, you will get an error as shown in the attached screenshot and when you try with the new app after adding all permissions, again that forbidden issues, you won’t be able to access anything. Looks like a developer at WIX is doing some changes and directly pushing the code to production and there is no Quality Assurance (QA) there to test.
What app are you “installing”? What are you trying to do?
Hi Yisrael
I am trying to install the app which I created at WIX Store. There are some serious issues at the developer end WIX. It was working fine but it suddenly starts giving issues.
Please explain - what app did you create? How did you create it? How are you installing it?
@yisrael-wix
Might be talking about the App Builder in testing?
https://support.wix.com/en/app-builder/getting-started
However, looking at the error message you are not getting a value for the replace.
@givemeawhisky Yes Exactly. There is some coding bug while installing, Please check it
@sumit51254 You will get better help in the App Builder Forum .
Your problem sounds like an “edge case” that you didn’t handle, and that didn’t occur when you first completed your app.
@givemeawhisky I am trying to integrate the app which I created at WIX store on my platform. I have the following apps created at WIX store. Integration was working fine but it suddenly starts giving issues.
@yisrael-wix had there been anything left at my end,Integration would have been stopped earlier, I am telling you for last 10-15 days integration was going good with the same app. but now for every app whether I use the existing one or with new one,I get the same issue.
@yisrael-wix on selecting site I get the same error which is shown above in the post.
@givemeawhisky on selecting any site I get the same error which is shown above in the post.
@sumit51254 You will get better help in the App Builder Forum .
You can also contact the Wix support team to report this issue and get assistance.
@lee1 Appreciated !
@yisrael-wix Are you sure they’re accepting registrations to the App Builder forum? I know I registered months ago and my account sits unapproved, unable to login.
You can sign up to the beta at the bottom of this page here.
https://www.wix.com/blocks
Although whether they are still accepting and approving invites is a question only those running the testing at Wix can tell you.
Follow Yisrael’s advice and go ask on the Wix App Builder’s own forum, where you should get dedicated help specifically for it. https://www.wix.com/blocks/forum
The App Builder is still in testing and by using it’s own forum to ask for help on issues or report things that you might think are bugs or issues for example, is a great way to help Wix and fellow users get the App Builder sorted out and hopefully bug free for a future stable release to the public.
As it is still in testing, they might have modified the code somewhere which breaks something somewhere else, all part of the testing stage and the need for users like yourself to report it to them. Plus, this might have already been mentioned in the forum itself or in the updates section too.
I have App Builder access, just not the forum. Maybe you have to use the same email address (a bit awkward for me), but that’s not made clear.
@lee1
Okay that is a weird one then, as if you have access to the App Builder during testing, then you should have access to the forum too.
I’m assuming that they simply check emails against the already signed up users of the App Builder in Wix itself, however I might be wrong.
However, it should only be a matter of days to know if get approved or not, perhaps Yisrael can try to poke them to see if they are awake or still accepting even 
Okay, I will check that
@givemeawhisky I’m not sure that access to the App Builder includes access to the forum. After all, having access to Corvid (development mode) doesn’t include access to the Corvid forum. As far as I know, access to the forum is by signing up.