.dat file becomes corrupted (windows)

[Kodeekk]

Saving file with "Little Endian NBT (With Header)":

[14:23:22] [Worker-Main-164/ERROR]: Exception reading C:\Program Files\MultiMC\instances\Actions & Stuff\.minecraft\saves\My World\level.dat
java.util.zip.ZipException: Not in GZIP format
	at java.base/java.util.zip.GZIPInputStream.readHeader(GZIPInputStream.java:199) ~[?:?]
	at java.base/java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:82) ~[?:?]
	at java.base/java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:114) ~[?:?]
	at knot/net.minecraft.class_2507.method_40059(class_2507.java:43) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2507.method_40058(class_2507.java:66) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2507.method_40057(class_2507.java:61) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_40035(class_32.java:312) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_54527(class_32.java:248) [client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_43418(class_32.java:179) [client-intermediary.jar:?]
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1789) [?:?]
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1781) [?:?]
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:511) [?:?]
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1450) [?:?]
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:2019) [?:?]
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187) [?:?]

Saving file with "GZip" compression:

[14:23:38] [Worker-Main-165/ERROR]: Exception reading C:\Program Files\MultiMC\instances\Actions & Stuff\.minecraft\saves\My World\level.dat
java.io.IOException: Invalid tag id: 95
	at knot/net.minecraft.class_4614$1.method_39878(class_4614.java:54) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_4614$1.method_39851(class_4614.java:74) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39851(class_2487.java:167) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_4614$class_6840.method_39854(class_4614.java:46) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2499$1.method_39851(class_2499.java:121) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39851(class_2487.java:167) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39851(class_2487.java:167) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_4614$class_6840.method_39854(class_4614.java:46) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2499$1.method_39851(class_2499.java:121) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39851(class_2487.java:167) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_53888(class_2487.java:130) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39852(class_2487.java:94) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_53888(class_2487.java:135) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2487$1.method_39852(class_2487.java:94) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2507.method_39855(class_2507.java:141) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2507.method_40058(class_2507.java:67) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_2507.method_40057(class_2507.java:61) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_40035(class_32.java:312) ~[client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_54527(class_32.java:248) [client-intermediary.jar:?]
	at knot/net.minecraft.class_32.method_43418(class_32.java:179) [client-intermediary.jar:?]
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1789) [?:?]
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1781) [?:?]
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:511) [?:?]
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1450) [?:?]
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:2019) [?:?]
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187) [?:?]