Getting compile errors, Ooops! Error parsing JSON: SyntaxError: Unexpected token 'B' "Build serv"

Hello support, I have an app that I have been developing for a long time. Yesterday I did an update and I have not been able to compile it. I don't have any errors internally. Apparently it's an internal error, that it doesn't recognize a json format...

1 Like

I have the same error :frowning:

compiling OK here

I can confirm this issue...

Technical Data to be Submitted:
notes = Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/ Safari/537.36
foundIn = nb190b
faultData = Error parsing JSON: SyntaxError: Unexpected token 'B', "Build serv"... is not valid JSON
projectId = 5677208057020416

@jis might want to check


Still compiling OK here :wink:

I have other projects that compile fine. But this one keeps giving error.

Keep trying, see if the problem repeats. I believe I know what is going on... and it may be related to work we did on the buildserver infrastructure today.

faultData = Error parsing JSON: SyntaxError: Unexpected token 'B', "Build serv"... is not valid JSON
projectId = 4961181847912448

yes, for my test project the error message keeps coming...
the funny thing is, my version from 2 days ago which built fine now also got that error...


The problem is repeats for all tryings.

For folks who are still getting errors, can you share the project aia file with me?

Yes of course.
Give me email to send a file.

just use PM


Send it to


OK. I resolved the problem, things should compile again.

For the curious... I updated the buildservers today to run Alpine Linux instead of Ubuntu, and I changed the front end from varnish to nginx. By default, nginx has a rather limited upload limit. Larger projects exceeded this. The fix was to configure nginx to accept larger projects (up to 50Mb, which is overkill).

There is a separate bug, which I will eventually get around to, which results in the App Inventor server not parsing the error from nginx, resulting the "We found a bug..." message.


Thank you very much for the fast service.., building works fine again....

Now all is OK.
Fast compiler!