1# Network Connection Management Error Codes
2
3> **NOTE**
4>
5> This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](../errorcode-universal.md).
6
7## 2100001 Invalid Parameter Value
8
9**Error Message**
10
11Invalid parameter value.
12
13**Description**
14
15This error code is reported if the parameter value is invalid.
16
17**Cause**
18
19The input parameter value is not within the valid value range.
20
21**Procedure**
22
23Check whether the input parameter value is within the valid value range.
24
25## 2100002 Service Connection Failure
26
27**Error Message**
28
29Failed to connect to the service.
30
31**Description**
32
33This error code is reported if a service connection failure occurs.
34
35**Cause**
36
37The service is abnormal.
38
39**Procedure**
40
41Check whether system services are running properly.
42
43## 2100003 System Internal Error
44
45**Error Message**
46
47System internal error.
48
49**Description**
50
51This error code is reported if a system internal error occurs.
52
53**Cause**
54
551. The memory is abnormal.
56
572. A null pointer is present.
58
59**Procedure**
60
611. Check whether the memory space is sufficient. If not, clear the memory and try again.
62
632. Check whether the system is normal. If not, try again later or restart the device.
64
65## 2101007 Callback Not Exist
66
67**Error Message**
68
69The callback does not exist.
70
71**Description**
72
73This error code is reported if a **callback** object to be unregistered does not exist.
74
75**Cause**
76
77The **callback** object has not been registered for activating a network or listening to network status changes.
78
79**Procedure**
80
81Before unregistering a **callback** object, make sure that it has been registered for activating a network or listening to network status changes.
82
83## 2101008 Callback Already Exists
84
85**Error Message**
86
87The callback already exists.
88
89**Description**
90
91This error code is reported if the same callback already exists.
92
93**Cause**
94
95The **callback** object has been registered for activating a network or listening to network status changes.
96
97**Procedure**
98
991. Check whether the **callback** object has been registered.
1002. If the **callback** object has been registered, use the registered **callback** object.
101
102
103## 2101022 Number of Requests Exceeding the Maximum
104
105**Error Message**
106
107The number of requests exceeded the maximum allowed.
108
109**Description**
110
111This error code is reported if the number of network requests exceeds the maximum.
112
113**Cause**
114
115The number of requests for activating a network or listening to network status changes has reached the maximum value.
116
117**Procedure**
118
119Locate the fault based on the "Over the max request number" log record.
120