# Porting FB 4 Projects to FinalBuilder 5

**URL:** <https://www.finalbuilder.com/forums/t/porting-fb-4-projects-to-finalbuilder-5/2885>\
**Category:** Bugs\
**Created:** [August 20, 2007, 11:15am UTC](https://www.finalbuilder.com/forums/t/porting-fb-4-projects-to-finalbuilder-5/2885 "2007-08-20T11:15:39Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![devrieskok](https://www.finalbuilder.com/forums/letter_avatar_proxy/v4/letter/d/ecc23a/32.png) [@devrieskok](https://www.finalbuilder.com/forums/u/devrieskok)\
**Post date:** [August 20, 2007, 11:15am UTC](https://www.finalbuilder.com/forums/t/porting-fb-4-projects-to-finalbuilder-5/2885/1 "2007-08-20T11:15:39Z")

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Hi,

While proting my FinalBuilder 4 projects to FinalBuilder 5 I ran into the following

1. Open a FB4 project in FinalBuilder 5  
2. Save As FinalBuilder 5 Project to the same folder as the FB4 Project  
3. Keep this Project open in FinalBuilder 5  
4. Open FB4 project in FinalBuilder 4, a&nbsp;Warning message states:  
&nbsp;&nbsp; Unable to load project  
&nbsp;&nbsp; Error: Unable to read log file: Log file is locked by another FinalBuilder instance  
  
This error will also occure when the FB4 Project is opened by FinalBuilder 4 and then by FinalBuilder 5. After a little research I found out that it concerned the .lck file. I can't remember this happening when I was porting FB3 projects to FinalBuilder 4

Regards Alfred

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**Author:** ![Vincent](https://www.finalbuilder.com/forums/user_avatar/www.finalbuilder.com/vincent/32/938_2.png) [@Vincent](https://www.finalbuilder.com/forums/u/Vincent)\
**Post date:** [August 20, 2007, 1:45am UTC](https://www.finalbuilder.com/forums/t/porting-fb-4-projects-to-finalbuilder-5/2885/2 "2007-08-20T01:45:50Z")

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Hi Alfred   
  
 The .lck file was new to FinalBuilder 4, it is used by the embedded database engine used for logging. The database engine allows us to do a lot more with the logging that was previously possible.