Compile error after adding Unity Collections package

After adding Unity Collections pakcage, I got this error

Library/PackageCache/com.unity.collections@1.1.0/Unity.Collections/xxHash3.cs(560,27): error CS0234: The type or namespace name 'umul128' does not exist in the namespace 'Common' (are you missing an assembly reference?)
Library/PackageCache/com.unity.collections@1.1.0/Unity.Collections/xxHash3.cs(582,27): error CS0234: The type or namespace name 'umul128' does not exist in the namespace 'Common' (are you missing an assembly reference?)
Library/PackageCache/com.unity.collections@1.1.0/Unity.Collections/xxHash3.cs(589,28): error CS0234: The type or namespace name 'umul128' does not exist in the namespace 'Common' (are you missing an assembly reference?)
Library/PackageCache/com.unity.collections@1.1.0/Unity.Collections/xxHash3.cs(825,22): error CS0234: The type or namespace name 'umul128' does not exist in the namespace 'Common' (are you missing an assembly reference?)

My platform is iOS.

The second answer of this link explains how to add Unity Collections pakcage

https://forum.unity.com/threads/how-do-i-add-the-collections-package.1138399/

Does anyone know how to fix this? Thank you.

[supiket]

I solved the issue in the following way:

1. Moved the com.unity.collections@<your_version> folder from <YourProjectRoot>/Library/PackageCache/ directory to <YourProjectRoot>/Packages/ directory.
2. Opened the file com.unity.collections@<your_version>/Unity.Collections/xxHash3.cs.
3. Changed the Common.umul128(...) calls to Unity.Burst.Intrinsics.Common.umul128(...) calls.

The reason for step 1 is that the Library directory is “volatile”, so when I edit the script without applying step 1, step 3 was undone with each Unity recompile.

[JamesW940516]

Thanks!!! @supiket Your solution saved my life. I am wondering that this issue has been fixed officially or not. I could not find any proper solution anywhere. Thanks again!!!