# Designer error - Cannot create PyString with non-byte value

**URL:** <https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795>\
**Category:** Ignition\
**Created:** [September 9, 2021, 8:16pm UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795 "2021-09-09T20:16:13Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![michal.ruda](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michal.ruda/32/27661_2.png) [@michal.ruda](https://forum.inductiveautomation.com/u/michal.ruda)\
**Post date:** [September 9, 2021, 8:16pm UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/1 "2021-09-09T20:16:13Z")

</div>

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/7/d75a3023d0e9ba9ca481545b4fb57f6b3ee7d067.png)

Hi. Can anybody help me with this? I am unable to open any project in the Designer.  
Thanks. Michal

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<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [September 9, 2021, 9:12pm UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/2 "2021-09-09T21:12:07Z")

</div>

Are you in contact with support? This forum isn’t an official support venue, and you’ll probably need to provide a .gwbk to assist in troubleshooting - that’s probably a better option for timely help.  
Do you recall creating a project script library/package called `nt`, by any chance?  
Is there any more stacktrace available?

---

<div class="post-metadata">

**Author:** ![michal.ruda](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michal.ruda/32/27661_2.png) [@michal.ruda](https://forum.inductiveautomation.com/u/michal.ruda)\
**Post date:** [September 10, 2021, 11:39am UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/3 "2021-09-10T11:39:54Z")

</div>

```auto
Traceback (most recent call last):
  File "C:\Users\ruda\.ignition\cache\gwignition.ruda.tech_8088\C0\pylib\site.py", line 68, in <module>
    import os
  File "C:\Users\ruda\.ignition\cache\gwignition.ruda.tech_8088\C0\pylib\os.py", line 59, in <module>
    from nt import *
java.lang.IllegalArgumentException: Cannot create PyString with non-byte value
	at org.python.core.PyString.<init>(PyString.java:57)
	at org.python.core.PyString.<init>(PyString.java:70)
	at org.python.core.PyString.<init>(PyString.java:74)
	at org.python.core.Py.newString(Py.java:643)
	at org.python.modules.posix.PosixModule.getEnviron(PosixModule.java:1291)
	at org.python.modules.posix.PosixModule.classDictInit(PosixModule.java:136)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.python.core.PyJavaType.init(PyJavaType.java:529)
	at org.python.core.PyType$Registry.createType(PyType.java:477)
	at org.python.core.PyType$Registry.addFromClass(PyType.java:426)
	at org.python.core.PyType$Registry.resolveType(PyType.java:352)
	at org.python.core.PyType$Registry$1.computeValue(PyType.java:208)
	at org.python.core.PyType$Registry$1.computeValue(PyType.java:202)
	at java.base/java.lang.ClassValue.getFromHashMap(Unknown Source)
	at java.base/java.lang.ClassValue.getFromBackup(Unknown Source)
	at java.base/java.lang.ClassValue.get(Unknown Source)
	at org.python.core.PyType.fromClass(PyType.java:2137)
	at org.python.core.imp.createFromClass(imp.java:655)
	at org.python.core.imp.loadBuiltin(imp.java:803)
	at org.python.core.imp.find_module(imp.java:747)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_module_level(imp.java:1350)
	at org.python.core.imp.importName(imp.java:1528)
	at org.python.core.ImportFunction. __call__ ( __builtin__.java:1285)
	at org.python.core.PyObject. __call__ (PyObject.java:433)
	at org.python.core. __builtin__. __import__ ( __builtin__.java:1232)
	at org.python.core.imp.importAll(imp.java:1647)
	at os$py.f$0(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/os.py:726)
	at os$py.call_function(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/os.py)
	at org.python.core.PyTableCode.call(PyTableCode.java:173)
	at org.python.core.PyCode.call(PyCode.java:18)
	at org.python.core.imp.createFromCode(imp.java:630)
	at org.python.core.imp.createFromSource(imp.java:583)
	at org.python.core.imp.loadFromSource(imp.java:944)
	at org.python.core.imp.find_module(imp.java:769)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_module_level(imp.java:1350)
	at org.python.core.imp.importName(imp.java:1528)
	at org.python.core.ImportFunction. __call__ ( __builtin__.java:1285)
	at org.python.core.PyObject. __call__ (PyObject.java:433)
	at org.python.core. __builtin__. __import__ ( __builtin__.java:1232)
	at org.python.core.imp.importOne(imp.java:1547)
	at site$py.f$0(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/site.py:628)
	at site$py.call_function(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/site.py)
	at org.python.core.PyTableCode.call(PyTableCode.java:173)
	at org.python.core.PyCode.call(PyCode.java:18)
	at org.python.core.imp.createFromCode(imp.java:630)
	at org.python.core.imp.createFromSource(imp.java:583)
	at org.python.core.imp.loadFromSource(imp.java:944)
	at org.python.core.imp.find_module(imp.java:769)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_first(imp.java:1198)
	at org.python.core.imp.load(imp.java:1016)
	at org.python.core.Py.importSiteIfSelected(Py.java:1842)
	at com.inductiveautomation.ignition.common.script.ScriptManager.<init>(ScriptManager.java:150)
	at com.inductiveautomation.ignition.common.script.ScriptManager.<init>(ScriptManager.java:108)
	at com.inductiveautomation.ignition.designer.DesignerContextImpl.<init>(DesignerContextImpl.java:163)
	at com.inductiveautomation.ignition.designer.IgnitionDesigner.loadProject(IgnitionDesigner.java:937)
	at com.inductiveautomation.ignition.designer.IgnitionDesigner$StartupProjectDialogHandler.lambda$new$2(IgnitionDesigner.java:2011)
	at java.base/java.lang.Thread.run(Unknown Source)
java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: Cannot create PyString with non-byte value

	at org.python.core.Py.JavaError(Py.java:547)
	at org.python.core.Py.JavaError(Py.java:538)
	at org.python.core.PyJavaType.init(PyJavaType.java:536)
	at org.python.core.PyType$Registry.createType(PyType.java:477)
	at org.python.core.PyType$Registry.addFromClass(PyType.java:426)
	at org.python.core.PyType$Registry.resolveType(PyType.java:352)
	at org.python.core.PyType$Registry$1.computeValue(PyType.java:208)
	at org.python.core.PyType$Registry$1.computeValue(PyType.java:202)
	at java.base/java.lang.ClassValue.getFromHashMap(Unknown Source)
	at java.base/java.lang.ClassValue.getFromBackup(Unknown Source)
	at java.base/java.lang.ClassValue.get(Unknown Source)
	at org.python.core.PyType.fromClass(PyType.java:2137)
	at org.python.core.imp.createFromClass(imp.java:655)
	at org.python.core.imp.loadBuiltin(imp.java:803)
	at org.python.core.imp.find_module(imp.java:747)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_module_level(imp.java:1350)
	at org.python.core.imp.importName(imp.java:1528)
	at org.python.core.ImportFunction. __call__ ( __builtin__.java:1285)
	at org.python.core.PyObject. __call__ (PyObject.java:433)
	at org.python.core. __builtin__. __import__ ( __builtin__.java:1232)
	at org.python.core.imp.importAll(imp.java:1647)
	at os$py.f$0(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/os.py:726)
	at os$py.call_function(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/os.py)
	at org.python.core.PyTableCode.call(PyTableCode.java:173)
	at org.python.core.PyCode.call(PyCode.java:18)
	at org.python.core.imp.createFromCode(imp.java:630)
	at org.python.core.imp.createFromSource(imp.java:583)
	at org.python.core.imp.loadFromSource(imp.java:944)
	at org.python.core.imp.find_module(imp.java:769)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_module_level(imp.java:1350)
	at org.python.core.imp.importName(imp.java:1528)
	at org.python.core.ImportFunction. __call__ ( __builtin__.java:1285)
	at org.python.core.PyObject. __call__ (PyObject.java:433)
	at org.python.core. __builtin__. __import__ ( __builtin__.java:1232)
	at org.python.core.imp.importOne(imp.java:1547)
	at site$py.f$0(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/site.py:628)
	at site$py.call_function(C:/Users/ruda/.ignition/cache/gwignition.ruda.tech_8088/C0/pylib/site.py)
	at org.python.core.PyTableCode.call(PyTableCode.java:173)
	at org.python.core.PyCode.call(PyCode.java:18)
	at org.python.core.imp.createFromCode(imp.java:630)
	at org.python.core.imp.createFromSource(imp.java:583)
	at org.python.core.imp.loadFromSource(imp.java:944)
	at org.python.core.imp.find_module(imp.java:769)
	at org.python.core.imp.import_next(imp.java:1158)
	at org.python.core.imp.import_first(imp.java:1198)
	at org.python.core.imp.load(imp.java:1016)
	at org.python.core.Py.importSiteIfSelected(Py.java:1842)
	at com.inductiveautomation.ignition.common.script.ScriptManager.<init>(ScriptManager.java:150)
	at com.inductiveautomation.ignition.common.script.ScriptManager.<init>(ScriptManager.java:108)
	at com.inductiveautomation.ignition.designer.DesignerContextImpl.<init>(DesignerContextImpl.java:163)
	at com.inductiveautomation.ignition.designer.IgnitionDesigner.loadProject(IgnitionDesigner.java:937)
	at com.inductiveautomation.ignition.designer.IgnitionDesigner$StartupProjectDialogHandler.lambda$new$2(IgnitionDesigner.java:2011)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: Cannot create PyString with non-byte value
	at org.python.core.PyString.<init>(PyString.java:57)
	at org.python.core.PyString.<init>(PyString.java:70)
	at org.python.core.PyString.<init>(PyString.java:74)
	at org.python.core.Py.newString(Py.java:643)
	at org.python.modules.posix.PosixModule.getEnviron(PosixModule.java:1291)
	at org.python.modules.posix.PosixModule.classDictInit(PosixModule.java:136)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.python.core.PyJavaType.init(PyJavaType.java:529)
	... 52 more

Ignition v8.1.10 (b2021090812)
Java: Azul Systems, Inc. 11.0.11

```

Hi. Thanks for the reply. This is a full trace of the error. I fresh installed Ignition 8.1.10 on the Ubuntu 20.04 server, tried Designer on two different Windows PCs with the exact same result, which u can see here. I did not contact the support, yet. I really do not know what `nt` is. Everything on the server and workstation comes directly from installation od the Ignition and Designer Launcher. The error shows up every time I try to open any project. Including the Sample Quick Start Project or a new one just created.

Thanks for your advice.

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [September 10, 2021, 2:40pm UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/4 "2021-09-10T14:40:24Z")

</div>

In the context the designer launcher is creating the new Designer instance, there’s an environment variable set with a non-ASCII name. That’s pretty unusual, especially since you’re encountering this on different machines; maybe it’s something being provided by your AD domain or other Windows setup?  
If the Ubuntu install has a desktop environment, you could try launching a designer there. You can see the names and values of the default environment variables on Windows pretty easily:  
[https://www.architectryan.com/2018/08/31/how-to-change-environment-variables-on-windows-10/](https://www.architectryan.com/2018/08/31/how-to-change-environment-variables-on-windows-10/)

---

<div class="post-metadata">

**Author:** ![xion8x8](https://avatars.discourse-cdn.com/v4/letter/x/cc9497/32.png) [@xion8x8](https://forum.inductiveautomation.com/u/xion8x8)\
**Post date:** [November 19, 2021, 3:01am UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/5 "2021-11-19T03:01:41Z")

</div>

Hi, i have encountered this issue recently on my laptop. is there a solution for this?

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [November 19, 2021, 3:32pm UTC](https://forum.inductiveautomation.com/t/designer-error-cannot-create-pystring-with-non-byte-value/50795/6 "2021-11-19T15:32:08Z")

</div>

Are you sure it’s the exact error from the OP of this thread? If so, have you looked for environment variables with non-ASCII names, per my last post?