# System.tag.exists ..... but it doesn't **URL:** \ **Category:** Ignition\ **Tags:** scripting\ **Created:** [November 19, 2021, 1:22am UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271 "2021-11-19T01:22:34Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![markrit](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/markrit/32/29635_2.png) [@markrit](https://forum.inductiveautomation.com/u/markrit)\ **Post date:** [November 19, 2021, 1:22am UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/1 "2021-11-19T01:22:34Z")
If I run the following in the script console ``` gnamePath = '[MQTT Engine]DCNET/MAP/S1/R1/B1/G10/Name' if system.tag.exists (gnamePath): print 'Tag Exists' ``` and a folder for [MQTT Engine]DCNET/MAP/S1/R1/B1/G10/ is present , BUT the tag “Name” is NOT present in that folder then this will print " Tag Exists" The function description is Checks whether or not a Tag with a given path exists. The folder has no tags in it is this the problem? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 19, 2021, 1:52am UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/2 "2021-11-19T01:52:54Z")
What version of Ignition is this happening on? ---
**Author:** ![markrit](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/markrit/32/29635_2.png) [@markrit](https://forum.inductiveautomation.com/u/markrit)\ **Post date:** [November 19, 2021, 3:46pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/3 "2021-11-19T15:46:08Z")
8.1.7 ---
**Author:** ![markrit](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/markrit/32/29635_2.png) [@markrit](https://forum.inductiveautomation.com/u/markrit)\ **Post date:** [November 19, 2021, 5:53pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/4 "2021-11-19T17:53:17Z")
Updated to 8.1.12 now getting this message ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/e/de396ef6048590f2f3add8f0fcd06dce110cb871.png) only file in this path is modules file. Tried uninstalling, and downloading designer for reinstall. No luck ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 19, 2021, 6:01pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/5 "2021-11-19T18:01:50Z")
Delete the `11.0.11.1` folder in that path and you should be able to launch. ---
**Author:** ![markrit](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/markrit/32/29635_2.png) [@markrit](https://forum.inductiveautomation.com/u/markrit)\ **Post date:** [November 19, 2021, 6:21pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/6 "2021-11-19T18:21:22Z")
That fixed the designer launch after upgrade . ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/6/3629a2a81df58d98607b456e5f1361af4fde2fc9.png) Still have issue with system.tag.exists ---
**Author:** ![WillMT10](https://avatars.discourse-cdn.com/v4/letter/w/7feea3/32.png) [@WillMT10](https://forum.inductiveautomation.com/u/WillMT10)\ **Post date:** [November 19, 2021, 6:31pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/7 "2021-11-19T18:31:42Z")
Have you tried refreshing the tag provider to make sure the folder is actually empty? I just ran a test in 8.1.9 and it worked as expected for me (empty folder and returned false when I checked for a non-existent tag in the empty folder). Edit: Just wanted to note that the provider I tested against does not use MQTT. ---
**Author:** ![markrit](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/markrit/32/29635_2.png) [@markrit](https://forum.inductiveautomation.com/u/markrit)\ **Post date:** [November 19, 2021, 6:52pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/8 "2021-11-19T18:52:27Z")
Yes. Did this in the tag browser same results. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 19, 2021, 7:11pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/9 "2021-11-19T19:11:59Z")
I think this might be a bug that is specific to the MQTT modules. I thought maybe it affected any ManagedTagProvider implementation but I just tested against the provider from the SDK example and it works as expected. I’d contact Cirrus Link or maybe paging @wes0johnson will work 🙂 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/6/96a21dda6b3e880523eaac55636a9af5a85a4a86.png) ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [November 19, 2021, 8:59pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/10 "2021-11-19T20:59:45Z")
This is not something I’ve seen before. I’m not sure how the MQTT Engine module could be causing this other than maybe with the way we configure the ManagedTagProvider. I believe some of the config options we use are different from the SDK example. I’ll take a look and see if I can repro this and isolate the cause. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 19, 2021, 9:00pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/11 "2021-11-19T21:00:57Z")
`system.tag.exists` expects QualityCode Bad\_NotFound to be returned after trying to read a tag that doesn’t exist. ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [November 19, 2021, 10:06pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/12 "2021-11-19T22:06:45Z")
Is this not something that is handled by the ManagedTagProvider itself? I just glanced at the SDK example and it doesn’t do anything explicitly around this that I can see… ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 19, 2021, 10:21pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/13 "2021-11-19T22:21:29Z")
Well, that’s what I thought, but like I said when I tested the MTP example it all works fine 😕 I’m not sure why it’s not behaving the same for tags from the MQTT provider. ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [November 19, 2021, 10:39pm UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/14 "2021-11-19T22:39:34Z")
I’ll do some digging on my side and see what I can find. ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [November 24, 2021, 1:04am UTC](https://forum.inductiveautomation.com/t/system-tag-exists-but-it-doesnt/53271/15 "2021-11-24T01:04:37Z")
So I think I figured this out. I was not able to reproduce with the SDK example, but I was with Engine. This is how I got it to happen: 1. I created an Edge Node with 3 tags under a single device and published from Transmission 2. I deleted one of the tags from the Edge side 3. I restarted MQTT Engine (this is key) 4. I published a new birth from the Edge This produced the following: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/3/13068f0f8a27ccbde0bf9f56bc68f3d59fd93786.png) The reason is that MQTT Engine does not persist tags. But, it does still persist the tag configuration. So, I think ‘tagExists’ looks to see if it is in the DB tag table - which does not necessarily mean it is visible in Designer. With this, I suspect the tag you are trying to look up did exist at one point and was never deleted from the Ignition Tag DB (via a delete event or similar). But, Engine has since been restarted which is why it is not visible in Designer. I believe that if you delete that tag from the DB, tagExists will properly return false.