# An internal error occurred during: "Building". Invalid index

**URL:** <https://forum.servoy.com/t/an-internal-error-occurred-during-building-invalid-index/20629>\
**Category:** Questions\
**Created:** [December 3, 2021, 6:18pm UTC](https://forum.servoy.com/t/an-internal-error-occurred-during-building-invalid-index/20629 "2021-12-03T18:18:29Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rafig](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.servoy.com/rafig/32/4463_2.png) [@rafig](https://forum.servoy.com/u/rafig)\
**Post date:** [December 3, 2021, 6:18pm UTC](https://forum.servoy.com/t/an-internal-error-occurred-during-building-invalid-index/20629/1 "2021-12-03T18:18:29Z")

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Hi all,  
I keep getting this error now on a large solution.  
I have looked and looked & tried and tried, but cannot work out what the issue is.  
I have re-installed Servoy from a fresh download.  
I have removed & re-cloned the source workspace from GIT.  
I have tried deleting Eclispe “.metadata” folder.  
I cannot stop this (& other errors now) occurring.  
I thought it might be down to some extra odd control characters in some of the JS files, but after using a tool to remove them, the errors are still threre.  
Almost every time I get an Eclipse error dialog, the word ‘index’ is in there, some I’m thinking it has to be something to do with my workspace/files.  
(Hence me trying extreme measure like search/replace on ‘\0x0D’ (ASCII 10, CR) in the JS files,  
thinking they may have been throwing something off)  
I admit that that this is only happening with one (very large) solution, & only since I upgraded to new M1 Mac  
Please can someone help or point me at what might be the issue??  
Thanks,  
Rafi

[EDIT] Next error is

```auto
An internal error occurred during: "Requesting Script AST from selection".Invalid index

```

This happens when I click on something like a variable & Eclipse tries to highlight (Mark) the other occurrences.

[EDIT2] And the next error is

```auto
An internal error occurred during: "Requesting Script AST from selection".Invalid index

```

This happens when I click on a method call & press ‘F3’ to jump to the actual method.

Hope this might point someone in the right direction.

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<div class="post-metadata">

**Author:** ![rafig](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.servoy.com/rafig/32/4463_2.png) [@rafig](https://forum.servoy.com/u/rafig)\
**Post date:** [December 8, 2021, 3:55pm UTC](https://forum.servoy.com/t/an-internal-error-occurred-during-building-invalid-index/20629/2 "2021-12-08T15:55:06Z")

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All fixed by update to new Mac M1 release  
[https://forum.servoy.com/viewtopic.php?f=1&t=23387](https://forum.servoy.com/viewtopic.php?f=1&t=23387)  
Thanks