topic Error mirroring tables on Prem SQL to Fabric in SQL database

Error mirroring tables on Prem SQL to Fabric

cseajs — Fri, 20 Jun 2025 21:06:05 GMT

We have 3 different databases on prem that I am trying to mirror to Fabric. Twenty of the tables sync with no issues but in all 3 instances there are 2 tables ( all the same tables) that are having issues syncing. It cannot be a data issue since the data is different in all 3 instances but the error makes me think it is a data / database issue. The error is below.

We encountered an error while parsing data file being used, please fix the file and try again. The error is: Exception reading the data file. Exception: Index was outside the bounds of the array., ErrorCode: InternalError, ErrorCode: InputValidationError

Re: Error mirroring tables on Prem SQL to Fabric

mabdollahi — Tue, 24 Jun 2025 06:40:16 GMT

Hi cseajs ,
The issue is likely due to unsupported or mismatched data types in those two specific tables; especially in primary keys or indexed columns. Even though the data is different, the table structure might include types like geometery, hierarchyid, or datetime2(7) that Fabric doesn't support well. Double-check the schema and data types across all three databases for those tables, clean up any null-only columns, and try syncing again.

Regards,
Mehrdad Abdollahi

Re: Error mirroring tables on Prem SQL to Fabric

v-sdhruv — Thu, 26 Jun 2025 09:51:39 GMT

Hi cseajs ,

The error suggests that the issue is likely related to how the data is being parsed—possibly due to malformed or inconsistent structure in the source files or tables you can follow the checks suggested by mabdollahi .

Additonally, you can
1.Try loading the tables manually into OneLake and use the “Load to Table” option to see if the issue reproduces.
2. Enable raw data preview in your pipeline to inspect malformed rows.

Hope this helps!
If the response has addressed your query, please accept it as a solution so other members can easily find it.
Thank you.

Re: Error mirroring tables on Prem SQL to Fabric

v-sdhruv — Mon, 30 Jun 2025 09:37:24 GMT

Hi cseajs ,

Just wanted to check if you had the opportunity to review the information provided. If the response has addressed your query, please accept it as a solution so other members can easily find it.
Thank you.

Re: Error mirroring tables on Prem SQL to Fabric

v-sdhruv — Mon, 07 Jul 2025 09:38:57 GMT

Hi @cseajs ,

Just wanted to check if you had the opportunity to review the information provided.
If any of the responses has addressed your query, please accept it as a solution so that other members can fint it easily.
Thank you.

Re: Error mirroring tables on Prem SQL to Fabric

Adityakumar — Tue, 08 Jul 2025 04:47:49 GMT

The “Index was outside the bounds of the array” error affecting the same two tables across all three database instances suggests a schema-related issue rather than a data problem. This typically occurs when Fabric mirroring encounters unsupported data types, complex column structures, or special characters in column names that the parsing engine cannot handle properly.

To resolve this, examine the schema of the failing tables compared to successful ones - look for unusual data types (like XML, geography, or deprecated types), special characters in column names, or complex constraints. You can also try testing individual columns by creating a subset table to isolate which specific columns are causing the parsing failure. Since the same tables fail consistently across different environments, the issue is likely in the table structure or metadata rather than the actual data content.

Re: Error mirroring tables on Prem SQL to Fabric

v-sdhruv — Thu, 10 Jul 2025 07:49:11 GMT

Hi cseajs ,

Just wanted to check if you had the opportunity to review the information provided.
If you still face any issues feel free to reach out, we would be happy to address your query
Thank you.