Not able to preview app in BAS

[RaminS]

Does anyone know why sometimes when trying to Preview Application in BAS (or $npm run start), the sign-in prompt comes up but does not authenticate against the backend gateway (on-premise).

This happens to all the developers in our team, once in a while, usually we're able to run the Fiori apps in BAS, but occasionally we're stuck at the sign-in prompt.

No errors in the console. I tried restarted the dev space, clearing browser cache, nothing helped.

Can anyone help us understand what's happening here?

Would appreciate it.

[RaminS]

Any ideas?

This is causing a lot of issues. Even in the same workspace, there'd be one project that runs and another that doesn't. No errors in the console.

[SugguSandeep]

Is this resolved ?

Did you connect any On Premise System ?

Explain Required in much more detail

Thank You,
Suggu Sandeep.
(SAP - The Best Run)

[RaminS]

It's not resolved.

Yes, we have on-premise backend.

thanks.

[RaminS]

What other detail do you need? There are no errors in the logs. The only way to resolve it to close all browser sessions and re-open. 

Not sure what other details I can provide.

[petr_stribrny]

Hello Ramin,

Based on your description it looks like a stored data issue. You wrote you tried to restart the dev space, to clear browser cache, and nothing helped. When you will be facing the issue again, could you please try to clear site data? Go to More Tools - > Developer Tools -> Application -> Storage -> Clear site data, and refresh the browser. You will need to sign in again, but at least you shouldn’t be forced to close all browser windows.

Best Regards,
Petr

[RaminS]

Hi Petr,

It didn't work, I cleared application data as you instructed. Now when I do npm run start, I don't even get a login prompt, I get this:

The run script stops mid-way:

[RaminS]

One more thing to add: today I was able to Preview one app, but not another.

The only way was to close all browser sessions and go back into BAS, now I can run both apps.

[petr_stribrny]

Hi Ramin

I’m sorry I was inaccurate - you have to clear site data & refresh the browser with the running BAS instance. A new preview command should bring the Sing in popup back and you should be able to sign in.
Best Regards,

Petr

[RaminS]

Thanks Petr, that worked! 🙂

How do other developers avoid this issue? This happens every time we leave the BAS session for a while, when we come back to it we get this error.

Do other developers always exit the BAS session before going for a coffee?

Thanks.

[petr_stribrny]

Hi Ramin,

Thanks for the confirmation the proposal works. I assume, the problem is, if you stay signed in and leave your machine, the token’s validity elapses, and the invalid token is used for the next sign in. You can reach out the BAS team to look into it. Anyway, I'd suggest always exit the BAS session before going for a coffee.

Best Regards,

Petr

[RaminS]

Petr,

This isn't working today, I cleared site data and refreshed the page, but the Preview keeps asking me to log in.

There are no site data in my BAS session.

[RaminS]

Petr, you mentioned "you can reach the BAS team". How do I reach the BAS team?

This is a very disruptive issue, we have to close all browser sessions every time to continue work in BAS.

.

[RaminS]

Any other ideas?

thanks.

.

[RaminS]

Even switching between Workspaces and going back to a Workspace that you worked on 15 minutes ago causes Preview Application not to work.

Surely this isn't normal.

[RaminS · Accepted solution]

After months of going back and forth with SAP support, they finally admitted that there is an issue with BAS and to fix it they need a new feature, which apparently will take a lot of work. Here's my final communication from SAP ticket:

So if you have problems previewing apps in BAS, the only way is to clear browser history, login to BAS again, and preview. Very annoying, but no other choice.

[AlexanderKunz1884 · Accepted solution]

We have the same problem

[ganesham500 · Accepted solution]

again getting the same issue!

[ganesham500 · Accepted solution]

In BAS navigate to Menage(settings Icon) -> Profilies -> Tick the check box for [/] Use this profile as the default for new windows Now you'll get ride of this issue.  

[RaminS · Accepted solution]

@ganesham500 that does not work. This has nothing to do with BAS profiles. The Preview function is not able to authenticate against the backend system because it's clinging on to an expired SSO token in the browser cache. Instead of establishing a new token it keeps trying to use the old SSO token and refuses to authenticate.

SAP knows the exact issue and how to resolve it (see screenshot in my answer above). They just haven't shown any interest in resolving it. I created a new ticket with SAP, so hopefully they'll fix it this time.