Dspace UI section PM2 error.

[IR Support]

My dspace Backend is working perfectly on domain, but UI section is slow and getting these error on pm2 log. I'm using dspace 7.6.1.

Suggest me the solution of the below error.

  .custom-file-input:lang(en)~.custom-file-label -> unmatched pseudo-class :lang
ERROR RangeError: Maximum call stack size exceeded
    at /dspace-ui/dist/server/main.js:1:557915
    at Array.forEach (<anonymous>)
    at DspaceRestResponseParsingService.process (/dspace-ui/dist/server/main.js:1:557907)
    at /dspace-ui/dist/server/main.js:1:557948
    at Array.forEach (<anonymous>)
    at DspaceRestResponseParsingService.process (/dspace-ui/dist/server/main.js:1:557907)
    at /dspace-ui/dist/server/main.js:1:557948
    at Array.forEach (<anonymous>)
    at DspaceRestResponseParsingService.process (/dspace-ui/dist/server/main.js:1:557907)
    at /dspace-ui/dist/server/main.js:1:557948

No _links section found at https://ir.inflibnet.ac.in/server/api
No _links section found at https://ir.inflibnet.ac.in/server/api
ERROR Error: undefined doesn't contain the link authn
    at /dspace-ui/dist/server/main.js:1:959609
    at /dspace-ui/dist/server/main.js:7:1882478
    at OperatorSubscriber2._this._next (/dspace-ui/dist/server/main.js:7:1842069)
    at OperatorSubscriber2.Subscriber2.next (/dspace-ui/dist/server/main.js:7:1792631)
    at /dspace-ui/dist/server/main.js:7:1882465
    at OperatorSubscriber2._this._next (/dspace-ui/dist/server/main.js:7:1842069)
    at OperatorSubscriber2.Subscriber2.next (/dspace-ui/dist/server/main.js:7:1792631)
    at /dspace-ui/dist/server/main.js:7:1921794
    at OperatorSubscriber2._this._next (/dspace-ui/dist/server/main.js:7:1842069)
    at OperatorSubscriber2.Subscriber2.next (/dspace-ui/dist/server/main.js:7:1792631)

Error: bind EADDRINUSE ::1:4000
    at listenOnPrimaryHandle (node:net:1885:18)
    at rr (node:internal/cluster/child:162:12)
    at Worker.<anonymous> (node:internal/cluster/child:112:7)
    at process.onInternalMessage (node:internal/cluster/utils:49:5)
    at process.emit (node:events:529:35)
    at process.emit (/dspace-ui/dist/server/main.js:7:2494285)
    at emit (node:internal/child_process:944:14)
    at _ZoneDelegate.invokeTask (/dspace-ui/dist/server/main.js:7:2180320)
    at Zone2.runTask (/dspace-ui/dist/server/main.js:7:2173302)
    at invokeTask (/dspace-ui/dist/server/main.js:7:2181808)

Thanks in Advance.

[DSpace Technical Support]

Hi,

It sounds like you *might* have multiple issues based on those error messages.

First, there's the error that says "bind EADDRINUSE ::1:4000".  That appears to be saying that you already have something running on port 4000 & PM2 is refusing to start something else on the same port.  You may need to see if that's accurate, and if so, stop whatever else is running on port 4000.  Here's some examples from StackOverflow on solving that issue: https://stackoverflow.com/questions/4075287/node-express-eaddrinuse-address-already-in-use-how-can-i-stop-the-process

Additionally, there's the error that says "No _links section found at", which implies a communication issue between the User interface and REST API.  This is one of our common installation issues with possible solutions listed at: https://wiki.lyrasis.org/display/DSDOC7x/Installing+DSpace#InstallingDSpace-%22No_linkssectionfoundat...%22errorfromUserInterface

If neither of those tips help, or you've already investigated those options, then we'd likely need more information about *when* these errors occur.  Are they occurring all the time?  Only occasionally?  Can you get the User Interface to work at all?

Tim