1.16.5 Forge Version Check

[Lunya]

Some time ago my mod could be updated via Forge Version Check. Today I noticed that when the mod checks for new versions, an error pops up.
I eventually realized that the problem was in the response status code, which was 304. After that, I fixed this problem and now the response status code is constantly 200.
But the version check error has not disappeared.
Even when requesting from a domain, the problem remains the same. Requests are processed through js express.

[23:12:53] [Forge Version Check/INFO]: [diamondworldhelper] Starting version check at http://127.0.0.1/update
[23:12:53] [Worker-Main-4/INFO]: [OptiFine] Multitexture: false
[23:12:54] [Forge Version Check/WARN]: Failed to process update information
java.lang.NullPointerException: null
	at net.minecraftforge.fml.VersionChecker$1.openUrlString(VersionChecker.java:160) ~[?:?]
	at net.minecraftforge.fml.VersionChecker$1.process(VersionChecker.java:187) [?:?]
	at net.minecraftforge.fml.VersionChecker$1$$Lambda$3709/1310274302.accept(Unknown Source) [?:?]
	at java.lang.Iterable.forEach(Iterable.java:75) [?:1.8.0_51]
	at net.minecraftforge.fml.VersionChecker$1.run(VersionChecker.java:128) [?:?]

https://imgur.com/a/0oR3PIL

Response:

net.minecraftforge.fml.VersionChecker:

[Lunya]

up

[Lunya]

This line of logs shows the url it is trying to access.

[23:12:53] [Forge Version Check/INFO]: [diamondworldhelper] Starting version check at http://127.0.0.1/update

[Lunya]

Thanks, this solved my problem.