diff --git a/docs/readthedocs/source/doc/Chronos/Overview/chronos_known_issue.md b/docs/readthedocs/source/doc/Chronos/Overview/chronos_known_issue.md
index 79a56bb1..e9a720bb 100644
--- a/docs/readthedocs/source/doc/Chronos/Overview/chronos_known_issue.md
+++ b/docs/readthedocs/source/doc/Chronos/Overview/chronos_known_issue.md
@@ -1,8 +1,13 @@
 # Chronos Known Issue
-## 1. Issue 1
+
+## Version Compatibility Issues
+
+### Numpy.ndarray size changed, may indicate binary incompatibility. Expected 88 from C header, got 80 from PyObject
+
 **Problem description**
 
-Numpy.ndarray size changed, may indicate binary incompatibility. Expected 88 from C header, got 80 from PyObject. 
+It seems to be a numpy compatibility issue, we do not recommend to solve it by downgrading Numpy to 1.19.x,
+when no other issues exist, the solution is given below.
 
 **Solution**
 * `pip install -y pycocotools`
@@ -11,10 +16,11 @@ Numpy.ndarray size changed, may indicate binary incompatibility. Expected 88 fro
 
 ---------------------------
 
-## 2. Issue 2
+### Cannot convert a symbolic Tensor (encoder_lstm_8/strided_slice:0) to a numpy array
+
 **Problem description**
 
-NotImplementedError: Cannot convert a symbolic Tensor (encoder_lstm_8/strided_slice:0) to a numpy array. 
+This is a compatibility issue caused by Tensorflow and Numpy 1.20.x
 
 **Solution**
 
@@ -22,11 +28,11 @@ NotImplementedError: Cannot convert a symbolic Tensor (encoder_lstm_8/strided_sl
 
 ---------------------------
 
-## 3. Issue 3
+### StanModel object has no attribute 'fit_class'
 
 **Problem description**
 
-StanModel object has no attribute 'fit_class', cause of pip, may be. 
+We recommend reinstalling prophet using conda or miniconda.
 
 **Solution**
 
@@ -35,7 +41,10 @@ StanModel object has no attribute 'fit_class', cause of pip, may be.
 
 ---------------------------
 
-## 4. Issue 4
+## Dependency Issues
+
+### RuntimeError: No active RayContext
+
 **Problem description**
 
 Exception: No active RayContext. Please call init_orca_context to create a RayContext.
@@ -49,11 +58,11 @@ Exception: No active RayContext. Please call init_orca_context to create a RayCo
 
 ---------------------------
 
-## 5. Issue 5
+### error while loading shared libraries: libunwind.so.8: cannot open shared object file: No such file or directory.
+
 **Problem description**
 
- Sed: error while loading shared libraries: libunwind.so.8: cannot open shared object file: No such file or directory.
-> Only happens when you run `source bigdl-nano-init`. 
+A dependency is missing from your environment, only happens when you run `source bigdl-nano-init`.
 
 **Solution**