Regex too complicated

[BobHatcher]

I am trying to upload a file that contains a mapping of SFDC ID's.

 DeveloperName,Label,Legacy_ID__c,Current_ID__c
 kA780000000CaRCCA0,kA780000000CaRCCA0,kA780000000CaRCCA0,kA30t0000004CuBCAU
 kA780000000CaRMCA0,kA780000000CaRMCA0,kA780000000CaRMCA0,kA30t0000004DfPCAU

When I upload this file I get the following error:

 Regex too complicated
 Error is in expression '{!upsertCustomMetadata}' in component <apex:commandButton> in page custommetadatarecorduploader: Class.CSVFileUtil.parseCSV: line 27, column 1
 Class.CustomMetadataUploadController.importCSVFileAndCreateUpdateCmdRecords: line 92, column 1
 Class.CustomMetadataUploadController.upsertCustomMetadata: line 52, column 1

I looked at the relevant line in CSVFileUtil and my file does not contain any double quotes or the substring DBLQT.

[DownstairsB]

I was getting this error on large files. I had to break mine into like 20 batches of 5k records because that's all this tool can handle. It took me about 2 days. Yeah.