Can't open sapui5 application extension from fiori launchpad

I am extending sap standard approval application in a Web IDE full stack. Made a few commits yesterday and at the end of the day, the application stopped working.

When I try to open the app from launchpad, I get nowhere and can only see errors in the console:

Web IDE shows no errors, so I am clueless. UI5 version is old 1.28.xx so maybe it behaves differently in new versions, at least the error message. It is my fault in the code, but still, this error should be somehow recognized by Web IDE if it is designed for UI5 apps.

Hm, i found the problem. The 'u' which I was getting the error was in the full name of formatter and the formatter name wasn't enclosed in apostrophes.

I created branches from commits before and found one working version. I have run it and it was okay. After that I deployed code from some commits later and it stopped working, but I was still in the app and somehow it showed different error description! voila..

I would found the error in the view sooner or later, but what I find frustrating is, that now I don't know how I was able to get this better error message.

I was thinking that when I put the whole link to the application with request to specific item and # with application name, I would get the message but this is not the case. Next time with the deployed code from the last commit and with specific link to app and item number it again showed the message from the question.

So solution to add '' into formatter

title="{parts:
     [{path: 'WorkitemText'}, {path: 'ScNumber'}, {path: 'CreatedByID'}, {path: 'OnBehalfOfID'} ],
     formatter: 'ui.s2p.srm.sc.approve.SRM_SC_APVExtension.util.Formatter.taskTitle'
     }"

The error was on missing '

 
...
formatter: u...
...